Full text of "Bulletin of the Geological Society of America"

See other formats

£.£V'<

BULLETIN

OF THE

GEOLOGICAL SOCIETY

AMERICA

VOL. 3

W J McGEE, Editor

ROCHESTER

POBLISHED I'.V THE SOCIETY
L892

MI-

COUNCIL FOR 1892

G. K. Gilbert, President

Sir J. William DawsojO

Vice-Presidents
T. C. Chamberlin, J

H. L. Fairchild, Secretary

I. C. White, Treasurer

Class of 1894
H. S. Williams,
N. H. Winchell,

Class of 1893
George M. Dawson, \ Members-at-large

John C. Branner,

Class of 1892
E. W, Claypole,
Charles H. Hitchcock, „

printers
Judd Sc Detweiler, Washington, D. C.

engravers
Moss Engravim; Co., 535 Pearl Street, New York

(H)

CONTENTS.

Page

Proceedings of the Summer Meeting; held at Washington, August 24 and 25,

1891 ; H. L. Fairchild, Secretary 1

Session of Monday Morning, August 24 2

Election of Fellows 2

Memorial Sketch of Alexander Winchell 3

A geological Map of South America (abstract); by Gtjstav Stein-

mann 13

On the Permian, Triassic and Jurassic Formations in the East Indian
Archipelago (discussion by C. A. White and L. F. Ward) ; by

August Rothpletz 14

Thermometamorphism in igneous Rocks; by Alfred Harker 16

Afternoon Session, August 24 23

The Plant-bearing Deposits of the American Trias; by Lester F.

Ward 23

Studies in problematic Organisms — the Genus Scolithus; by J. F.

James 32

The Tertiary Iron Ores of Arkansas and Texas ; by R. A. F. Pen-
rose, Jr 44

Sandstone Dikes in northwestern Nebraska ; by Robert Hay 50

Evening Session of Monday, August 24 55

Session of Tuesday Morning, August 25 56

Eulogium of Alexander Winchell 56

The Eurypterus Beds of Oesel as compared with those of North

America (abstract) ; by Friedricii Schmidt 59

On the marine Beds closing the Jurassic and opening the Cretaceous,

with the History of their Fauna ; by Alexis Pavlow 61

Quaternary Changes of Level in Scandinavia ; by < Jrrard de ( !eer. 65
The " Black Earth " of the Steppes of southern Russia ; by A. N.

Krassnof 68

On the Existence of the Dinotherium in Roumania; by Gregoire

Stefanesctj 81

Afternoon Session, Tuesday, August 25 83

The Eleolite-Syenite of BeemerviUe, New Jersey (abstract); by J.

F. Kemp 83

Notes on the Texas-New Mexican Region ; by R. T. Iln.i 85

The Relation of the American and European echinoid Faunas; by

J. W. Gregory 101

The Missouri Coal Measures and the Conditions of their Deposition;

by Arthur Winslow 109

The Pelvis of a Megalonyx and other Bones from Big Bone Cave,

Tennessee ; by J AMES M. S AFFORD 121

The ( lienegas of southern ( ialifornia ; by E. W Hilgard 124

The Chattahoochee Embaymenl ; by L. C. Johnson L28

\t g^ till)

- ■ ■ i

iv BULL. GEOL. SOC. AM., VOL. 3.

Page
Peculiar geologic Processes on the Channel Islands of California

(abstract) ; by Lorenzo G. Yates 133

Inequality of Distribution of the englacial Drift ; by Warrkx

Upham 134

Effects of Drought and Winds on alluvial Deposits in New Eng-
land ; by Homer T. Fuller 148

A Deep Boring in the Pleistocene near Akron, Ohio ; by E. W.

Claypole 150

Preliminary Notes on the Discovery of a vertebrate Fauna in Silurian (Ordo-

vician) Strata ; by C. D. Walcott 153

Certain extra-morainic Drift Phenomena of New Jersey; by P. D. Salisbury. 173
On the northward and eastward Extension of the pre-Pleistocene Gravels of

the Mississippi Basin ; by P. D. Salisbury 183

The Mannington Oil Field and the History of its Development; by I. C.

White 187

Fossil Plants from the Permian Beds of Texas ; by I. C. White 217

Notes on the Geology of the Valley of the middle Rio Grande ; by E. T.

Dumble 219

Eleolite-Syenite of Litchfield, Maine, and Hawes' Hornblende-Syenite from

Red Hill, New Hampshire ; by W. S. Bayley 231

A Revision and Monograph of the Genus Chonophyllum ; by W. H. Sherzer. . 253

The Principal Mississippian Section ; by C. R. Keyes 283

Two Montana Coal Fields ; by W. H. Weed 301

Paleozoic Formations of southeastern Minnesota ; by C. W. Hall and F. W.

Sardesox 331

Geology of the Tavlorville Region of California ; by J. S. Diller 369

Jura and Trias at Tavlorville, California ; by Alpheus Hyatt 395

Stratigraphy and Succession of the Rocks of the Sierra Nevada of California ;

by J. E. Mills 413

The Geology of the Crazy Mountains, Montana ; by J. E. Wolff 445

Proceedings of the Fourth Annual Meeting, held at Columbus, Ohio, December

29, 30, and 31, 1891 ; H. L. Fairciiild, Secretary 453

Session of Tuesday, December 29 454

Election of Officers and Fellows 454

Memorial of John Francis Williams 455

Fossil Plants from the Wichita or Permian Beds of Texas (discus-
sion by E. W, Claypole, Alpheus Hyatt and E. T. Dumble); by

I. C. White 459

Secondary Banding in < ineiss ; by William II. Hobbs 460

Paleozoic Formations of southeastern Minnesota (discussion by W J
McGee and C. W. Halle by C. W. Hall and F. W. Sardeson.. . . 4(54

Evening Session of Tuesday. December 29 465

Session of Wednesday. December 30 466

Report of the ( ouncil 466

Second Annual Report of the Committee on Photographs 470

Notes on the Geology of the Valley of the middle Rio Grande (dis-
cussion by W J McGee) ; by E- T. Dumble 483

CONTENTS. V

Page
Relationship of the glacial Lakes Warren, Algonquin, Iroquois and

Hudson-Champlain (abstract) ; by Warren Upham 484

The Iroquois Shore north of the Adirondacks; by J. W. Spencer. . 488
Channels over Divides not Evidence per se of glacial Lakes ; by J.

\Y. Spencer 491

Notes on the Geology of the Yukon Basin (abstract) ; by C. W.

Hayes 495

Geology of the Pribilof Islands ; by J. Stanley-Brown 496

Session of Thursday, December 31 500

The Gulf of Mexico as a Measure of Isostasy (abstract) ; by W J

McGee 501

Supposed interglacial Shell-beds in Shropshire, England ; by G. F.

Wright 505

The Champlain Submergence (abstract) ; by Warren Upiiam 508

Note on the Middleton Formation of Tennessee, Mississippi and

Alabama ; by J. M. Sapford 511

Paleaster eucharis ; by A. H. Cole 512

On the Structure and Age of the Stockbridge Limestone in the A7er-

mont Valley ; by T. N. Dale 514

A Contribution to the Geology of the Great Plains ; by Robert

Hay 519

List of Officers and Fellows of the Geological Society of America 522

Index to Volume 3 531

ILLUSTRATIONS.

Frontispiece — Portrait of Alexander Winciiell 1

Plate 1 — Penrose: Map showing the Tertiary Iron Ores in Arkansas and

Texas 45

" 2 — De Geer : Map of the late glacial marine Area in southern

Sweden 65

3 — Walcott: Silurian (Ordovician) Fish Remains from Colorado 172

" 4 " Silurian (Ordovician) Fish Remains from Colorado 172

5 Microscopic Sections of Silurian (Ordovician) Fish Re-
mains fr< >m Colorado 172

6— -White : Map of " Big Injun " Oil Belt 216

" 7 — Bayley : Mien (structure of Litchfieldite (2 figures) 252

" s — Sherzer : The < ienus < Tionophyllum (7 figures) 282

" 9 — K eyes : The Principal Mississippian Section 283

" 10 — Hall and Sardeson : Map and Profile of southeastern Minnesot.a.. 331

" 11 " Paleozoic Rocks of Minnesota (2 figures) 368

" 12 "' Thin Sections of Minnesota Paleozoic Rocks

(6 figures) 368

" 13 — Mills: Sketch Map of pre-Mesozoic arid Mesozoic Rocks 413

' " 14 — Hobbs : Secondary Banding in < rneiss 160

" 15 — Cole: I'lthit*/, /• eucharis, 1 [all 513

" Hi — Dale: Map of the Vermont Valley 514

Vi BULL. GEOL. SOC. AM., VOL. 3.

Pns*e

Proceedings (Washington) : Figure 1 — Scolithus shepardi 32

2 " n nicalis 33

3 " linearis 34

« « << ^ « u 34.

" " " 5 " clintonensis 35

G " linearis 36

" " " 7 — Planolites annvlarius 36

" " " 8 — Scolithus canadensis 37

" " " 9 " minutus 38

10 " " 38

11 " tuberosus 39

12 " woodi 39

" " " 13 " " 40

" " " 14 — Eophyton (Scolithus) dispar 41

" 15— Scolithus delicatulus 41

" " " 16 — Ideal Section showing the Mode of

Occurrence of the nodular Ores 46

" " " 17— Ideal Section showing the Mode of Oc-
currence of the laminated Ores. ... 47

" " " 18— Sandstone Dike number 1 51

19— Eastern End of Dike number 1 52

20— Dike number 2 53

(1 It II .)1 II II II XJ.

" " " 22— General View of Dike number 2 55

" " " 23— The Development of the toelemnitie

Fauna at the End of the Jurassic
and the Beginning of the Cretaceous. 62

" " " 24— Section through Manzati Valley 82

25— Sketch Map of Missouri 109

26— Ideal Section through the Ozark Up-
lift Ill

27— Ideal Section of the Coal Measures of

Missouri and Iowa 115

" " " 28— Ideal Section of the Coal Measures of

Missouri and Iowa restored to hori-
zontal Attitude 116

" " " 29 — Ideal Representation of the Beginning

of Coal Measure Deposition 116

" " " 30 — Ideal Representation of a complete

Cycle of Deposition of Coal Meas-
ures, and of their Mode of Accumu-
lation 117

" " " 31— Ideal Illustration of the Accumulation

of the Coal Measures 119

" " " 32 — Ideal Representation of the Missouri

Coal Measures 119

Walcott: Figure 1— Diagramatic Section of the Canyon City Silurian (Ordo-

vician) Rocks 154

ILLUSTRATIONS. VI 1

Page
Bayley : Figure 1 — Map showing 1 Ustribution of Eleolite-Syenite in the Towns

of Litchfield and West Gardiner, Maine 233

" " 2 — Occurrence of Nepheline and Sodalite in Feldspar 248

" " 3— Eleolite-Syenite from Red Hill 248

Weed: Figure 1 — Sketch Map of Montana showing Location of Coal Fields. . 302
" 2— Section at Belt Butte 306

3 " on Belt Creek 307

4 " " Sand Coulee 313

" 5 " at Sandcoulee 314

" " 6 — Sections revealed by Drilling at Sandcoulee 315

" " 7 — Section of Sandcoulee Coal Seam 316

8 " near Belt Creek 319

" .9 " in Belt Field 310

" "11 1— Sections of C< >al Seams of the Great Falls Field 320

11— Section at Watson Mine 321

" 12 " " Armington 321

13— ( oal Seams of Red Lodge Mines 327

Hall and Sardeson : Figure 1— Fault in the Magnesian near Hastings, Minne-
sota 344

" " 2 — Unconformity of the Saint Peter on the Mag-

nesian and the Conformity of the Trenton

on the Saint Peter 35

" " 3 — Minor Faults and Color Markings of the Saint

Peter Sandstone at south Saint Paul ...... 354

" " 4 — Diagramatic Sketch showing the Relations of

the Magnesian, Saint Peter and Trenton. . . 355

" " 5 — Classification of the Lower Silurian 359

" " 6 — Lenticular Segregations of Fossils in the Blue

Limestone, Minneapolis 360

" " 7 — Lenticular Segregations of Fossils mtheSticto-

pora Bed, Saint Paul 362

DlLI/ER: Figure 1— < ieneral Section through the Tayloiville Region 377

" " 2 — Section of Genesee Valley near Robinson's 378

" 3-^Tura-Trias Unconformity 380

" " 4 — Section on northeastern Slope of Grizzly Mountain 381

" " 5— Eastern Slope of Mount Jura 385

" " 6 — Section through Mount Jura 385

" 7 " near Indian village 385

" " s " " Donnerwirth's 385

9— Northeastern Slope of Grizzly Mountain 390

Proceedings (Columbus): Figure 1 — Section uearGreal Barrington 461

ti a a 9 " " « " 4lll

" " " 3 — Cleavage and Bedding near Great Bar-
rington 462

" " " 4 — Structure of Hopkins-Searles Quarry 462

" " " 5 — Section through Rutland-Danby Ridge. . . 516

" " " 6 — Structure of Hyolithes Limestone 517

" " 7— General Section on the 103d Meridian. .. 521
(17 plates, 72 figures.)

PUBLICATIONS OF THE GEOLOGICAL SOCIETY OF AMERICA.

Regular Publications.

The Society issues a single serial publication entitled Bulletin op the Geolog-
ical Society of America. This serial is made up of proceedings and memoirs, the
former embracing the records of meetings, with abstracts and short papers, lists of
Fellows, etc., and the latter embracing the larger papers accepted for publication.
The matter is issued, soon as possible after acceptance, in covered brochures, which
are at once distributed to Fellows and exchanges. The brochures are arranged for
binding in annual volumes, which are elaborately indexed.

The Bulletin is sold to Fellows and the public either in full volumes or in sepa-
rate brochures. The volume prices are, to Fellows a variable amount depending
on the cost of publication ; and to libraries and the public the fixed amounts given
below. The brochure prices for volumes 1 and 2 are given on pages ix-xi of volume
2; the prices for the brochures of volume 3 are given below.

Volume 1, covering the work of the Society from the organization in 1888 to the
end of 1889, comprises 593 + xii pages, 13 plates and 51 cuts. Price to Fellows, §4.50 ;
to libraries, S5.00 ; to the public, $10.00.

Volume 2, covering the work of the Society for L890, romprises 662 + xiv pages,
2:; plates and (13 cuts. Price to Fellows, $4.50 ; to libraries, $5.00 ; to the public, $10.00.

Volume 3, covering the work of the Society for 1891, is now complete, and com-
prises 541 + xii pages, 1 7 plates and 72 figures. Price to Fellows. $4.00 ; to libraries,
$5.00; to the public, $10.00. The volume is made up of 15 brochures as follows:

bkochURE. p.6ES. p,v,„, w™. ;:;:;;:;- j;--,;;;,.

Proceedings of the Summer Meeting

held at Washington. H. L. Fairchild,

Seen tary 1-152 0-2 1-32 $1.90 $3.75

Preliminary Notes on the Discovery of a

vertebrate Fauna in Silurian (Ordovi-

cian) Strata. C. D. Walcott 153-172 3-5 1 .30 .60

Certain extra-morainic Drift Phenomena

of New Jersey ; On the northward and

eastwai'd Extension of the pre-Pleisto-

cene Gravels of the Mississippi basin.

R. 1). Salisbury 173-186 .15 .25

The Mannington Oil Field and the His-
tory of its Development ; Fossil Plants

from the Permian Beds of Texas. I.

C. White 187-218 6 40 .75

Notes on the Geology of the Valley of

the middle Rio Grande. E. T. Dum-

ble 219-230 10 .20

Eleolite-Syenite of Litchfield, Maine, *

and Hawes' Hornblende-Syenite from

Red Hill, New Hampshire. W. S.

Bayley 231-252 7 1-3 .30 .55

(viii)

PUBLICATIONS.

Brochure.

Pages. Plates. Fioures.

A Revision and Monograph of the Genus

Chonophyllum. W. H. Sherzer 253-282 8

The principal Mississippian Section. C.

R. Keyes 283-300 9

Two Montana Coal Fields. W. II.

Weed 301-330

Paleozoic Formations of southeastern

Minnesota. C. W. Hall and V. W.

Sardeson 331-368 10-12

Geology of the Taylorville Region of

California. J. S. Diller 369-394

Jura and Trias at Taylorville, California.

Alpheus Hyatt 395—412

Stratigraphy and Succession of the Rucks

of the Sierra Nevada of California. J.

E. Mills 413—144

The Geology of the Crazy Mountains,

Montana." J. E. Wolff 445-452 .

Proceedings of the Fourth Annual Meet-
ing, held at Columbus. H. L. Fair- f 453-541 \

child, Secretary \ i-xii /

14-16

Puicf. TO

Kill ows.

.20

1-13

.35

1-7

.50

1-9

.30

.15

.30

.10

1-7

1.15

Price to
the Public.

.70
.40
.70

1.00
.55
.30

.60
.15

2.25

Irre< ; r l a R Publications.

In the interests of exact bibliography, the Society takes cognizance of all publi-
cations issued either wholly or in part under its auspices. Each author of a
memoir receives 30 copies without cost, and is authorized to order any additional
number at a slight advance on cost of paper and presswork ; and these separate
brochures are identical with those of the editions issued and distributed by the
Society. Contributors to the Proceedings also are authorized to order any number
of separate copies at a slight advance on cost of paper and presswork ; but such
separates are bibliographically distinct from the brochures issued by the Society.

The following separates of parts of volume 3 have been issued :

Editions uniform with the Brochures of the Bulletin.

Pages 153-172, plates 3, 5—130 copies. March

173-186,

130

L87-218, plate

-330

219-230,

130

231-252, plate

230

253-282, ':

- 30

283 -300, " .

- 30

301-330,

331-368, plates 10,

L2-

-130

369 394,.

•

230

395-412,

280

113 4)1, plate

13-

-100

445-452,

March

15,

L892

31,

April

15,

•_'_',

June

May

24,

June

• »

26,

23,

July

15,

August

1 1 Bull. G bol. Soc. Am., Vo

l.N'll.

BULL. GEOL. SOC. AM., VOL. 3.

Special

F Editions.*

Pages

3-13f,

frontispiece-

-100 copies.

March

25,

1892.

With covers. %

1-1- 15,

Novembei

■30,

1891.

Without (

covers.

Page

15,

30,

Pages

16- 22,

100

March

19,

1892.

23- 31,

100

January

32- 44,

■>■>

44- 50,

plate

-100

March

24,

With

50- 55,

100

19,

Without

56- 59,

100

25,

With

59- 60,

19,

Without

61- 64,

19,

65- 68,

plate

-100

24,

With

68- 79,

19,

Without

Page

80,

19,

Pages

80- 81,

19,

81- 83,

200

19,

With

83- 84,

19,

Without

85-100,

300

February

26,

With

101-1 Oil,

100

March

19,

Without

109-121,

200

19,

With

121-123,

19,

Without

124-127,

200

19,

128-132,

19,

134-148,

19,

148-149,

19,

150-151,

19,

455-458,

100

November 18,

With

460-464,

plate

14—150

18,

Page

464,

15,

Without

Pages 470-483,

15,

483-484,

15,

484-487,

15,

488-495,

200

15,

495-496,

15,

496-500,

150

15,

501-504,

15,

505-508,

15,

508-511,

15,

512-514.

plate

15-

-200

15,

514-519,

16-

-100

!•>,

510-521,

100

15,

523-530,

l->,

viii-ix,

15,

* Bearing the imprint ["From Bull. Geul. Soc. Am., Vol. 3, 1891'*].
f Fractional pages sometimes included.
X Pages 56-59 inclosed in same cover.
i With pages 3-13 and frontispiece.

PUBLICATIONS. XI

Reprints.

The matter published by the Society is occasionally reprinted, sometimes in
part only, sometimes in extended or otherwise modified form, and incidental cog-
nizance is taken of such reprints. The following reprint has been noted :

osophy || By | Charles Rollin Keyes. [ 1892. | | Washington : | Judd &

Detweiler, Printers | 1892.

ERRATA.

JO,

line L5

from bottom ;

for

" reenfore"

rem

/ reenforce.

101,

'• aquatic "

agnostic.

L03,

" k'ursli in "

Karsteni.

105,

lop

"twinned "

tumid.

105,

1 !

"ths"

tin'.

L06,

"Centra"

( 'entral.

106,

• »

• >

bottom

"probabilities"

probahilities.

107,

a •

"Asterostoma, n. .-

;p." "

Archseopreuster ab-
ruptus, < Ireg.

107,

•a

"Asterostoma "

ArchxopreuKliT.

l.-.l,

ill <

3ut ;

"Freemonl "

Fremont.

ODD

166,

" Sawyer "

Sawyer's farm.

233,

" Spaulding Sch,

i) a

Spaulding's farm.

369,

line 1 from bottom

" Northern "

North.

373,

top

" northern "

North.

373,

" tufaceous "

tufFaceous.

373,

bottom

"Trias"

bias.

375,

top

" tufaceoua "

tullaceous.

378,

bottom ;

aft

r " Section " insert

on northern sid\ .

378,

0-4

for

" tufaceous "

read tuflaceous.

380,

after "Unconformity "

insert

u a *<! it I li ir este rn

I > much of Piicrs

Ravine.

381,

ill

ml ;

to left of " X. E." insert

Genesee.

381,

line !•")

from

bottom :

aft

er " Mountain "

through Oenesee,

389,

top;

for

"Northern"

read North.

389,

" northern "

s.w

Srrzzly Mt.

Nortb.

N.t
Indian Creek

390 ; ./'"'■ defective cut substitute

391, line

392, lines •_'.:, 20,
:;;»:;, line

7 from bottom ; for k' northern " read North.

S " to),

a a

(xii)

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 1-152, frontispiece, pls. 1, 2

PROCEEDINGS OF THE SUMMER MEETING HELD AT
WASHINGTON AUGUST 24 and 25, 1891

H. L. FAIRCHILD, Secretary

ROCHESTER

PUBLISHED BY THE SOCIETY

March, 1892

x*L-

jUlv c^^L^TO^dxJJU

Bull. Geol. Soc. Am., Vol. :'., 1891.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP. 1-152, FRONTISPIECE, PLS. 1, 2 MARCH 9, 1892

PROCEEDINGS OF THE SUMMER MEETING, HELD AT
WASHINGTON, AUGUST 24 AND 25, 1891.

H. L. Fairchild, Secretary.

CONTENTS.

Page.

Session of Monday Morning, August 24 2

Election of Fellows 2

Memorial Sketch of Alexander Winchell 3

A geological Map of South America (abstract) ; by Gustav Steinmann 13

On the Permian, Triassic, and Jurassic Formations in the East Indian

Archipelago (discussion by C. A. White and L. F. Ward); by August

Rothpletz 14

Thermometamorphism in igneous Rocks ; by Alfred Harker 1(>

Afternoon Session, August 24 23

Tin- Plant-bearing Deposits of the American Trias ; by Lester F. Ward . . . 23

Studies in problematic Organisms — the Genus Scoliihus ; by J. F. James . . 32

The Tertiary Iron Ores of Arkansas and Texas ; by R. A. F. Penrose, Jr. . 44

Sandstone Dikes in northwestern Nebraska ; by Robert Hay 50

Evening Session of Monday, August 24 .1.")

Session of Tuesday Morning, August 25 56

Eulogium of Alexander Winchell .">(>

The Eurypterus Beds of Oesel as compared with those of North America

(abstract) ; by Friedrich Schmidt 59

On the marine Beds closing the Jurassic and opening the Cretaceous, with

the History of their Fauna ; by Alexis Pavlow (il

Quaternary Changes of Level in Scandinavia ; by Gerard de < reer 65

The "Black Earth" of the Steppes of southern Russia; by A. \. Krassnof. 68

< )n the Existence of the Dinotherium in Roumania ; by ( fregoire Stefanescu . 8 1

Afternoon Session, Tuesday, August 25 83

The Elseolite-Syenite of Beemerville, New Jersey (abstract); by J. F. Kemp. 83

Notes on the Texas-New .Mexican Region ; by Robert T. Hill 85

The Relation of the American and European echinoid Faunas; by John

W. Gregory 101

The Missouri Coal Measures and the Conditions of their Deposition; by

Arthur Winslow L09

The I 'el vis of a Megalonyx and other I Jones from Big Bone Cave, Tennessee ;

by .lames M. Safford L21

The * !ienegas of southern ( lalifornia ; by E. W 1 [ilgard 121

The < lhattahoochee Embaymenl ; by Lawrence ( '. Johnson L28

L— Bi ii. Geol. 8oc, Am., Vol. 3, 1891.

2 PROCEEDINGS OF WASHINGTON MEETING.

Page.

Peculiar geologic Processes on the Channel Islands of California (abstract i ;

by Lorenzt i < r. Yates 133

Inequality of Distribution of the englacial Drift; by Warren Upham 134

Effects of Droughts and Winds on alluvial Deposits in New England; by

Homer T. Fuller .148

A deep Boring in the Pleistocene near Akron, Ohio; by E. W. Claypole . . L50

Session of Monday Morning, August 24.

The Society met in the law lecture-room of Columbian University at
9.45 o'clock a. m., Vice-President G. K. Gilbert in the chair.

In the absence of Dr. J. C. Welling, President of the University, who
was expected to welcome the Society, Acting President Gilbert spoke a
few words of greeting, and, in behalf of the Society, welcomed the in-
vited foreign guests.

ELECTION OF FELLOWS.

The Secretary announced the result of the balloting for the election of
Fellows as follows :

William P. Blake, New Haven, Connecticut. Alining engineer.

Clarence Raymond Claghorn, B. S., M. E., Birmingham, Alabama. Economic

geologist and mining engineer ; now working on the geology of coal.
David T. Day, A. B., Ph. D., Washington, D. C Chief of division of mining

statistics and technology, United States Geological Survey.
Maj. Clarence E. Dutton, Ordnance Department, U S. A., San Antonio, Texas.

Formerly of the United States Geological Survey.
Toiix Eyerman, Easton, Pennsylvania. Instructor in La Fayette College ; Associate

editor of the Journal of Analytical Chemistry, and of the American Geologist ;

now engaged in paleontology.
Eugene Rudolphe Faribault, C E., Ottawa, Canada. Field geologist on Geo-
logical Survey explorations in Nova Scotia.
William Herbert Hobbs, B. Sc, Ph. D., Madison, Wisconsin. Assistant professor

of mineralogy, University of Wisconsin; Assistant geologist, United States

< reological Survey. Engaged in the study of crystalline schists.
Walter Proctor Jenney, E. M., Ph. I)., Washington, D. C- Mining engineer,

and Geologist, United States ( reological Survey ; now engaged in general geology

of zinc and lead deposits of the Mississippi valley.
James Putnam Kimball, Ph. D , Washington, D. C Geologist, now engaged in

private practice.
George Edgar Ladd, A. B., A. M., Jefferson City, Missouri. Assistant geologist,

Missouri Geological Survey ; now engaged in economic geology.

MEMORIAL OF ALEXANDER WINCHELL. 6

James Rieman Macparlane, A. B., Pittsburg, Pennsylvania. Editor of the second

edition of the American Geological Railway Guide.
William II. Niles, Ph. B., M. A., Cambridge, Massachusetts. Teacher of geology .

Timothy William Stanton, B. S., Washington, D. C. Assistant paleontologist,
United States Geological Survey.

The following memorial of the deceased President of the Society, Dr.
Alexander Winchell, was read by Professor N. H. Winch ell :

MEMORIAL SKETCH OF ALEXANDER WINCHELL.

Fellow Geologists ;

It is because of the courteous persuasion of some of the scientific and
personal friends of my brother that I have undertaken the sad privilege
of saying a few words in his memory. It were, perhaps, on some ac-
counts more fitting that alien tongues should discharge this duty ; but
on other accounts it were more appropriate that a personal friend sin mid
speak of him, from the* intimacy of his acquaintance and from the love
that springs from many years of community of interests and constant
intercourse. To you who knew Alexander Winchell well, no words that
I shall utter, however they may be tinged by a brother's partiality, will
appear extravagant; and to you who did not know him well, I shall
hope to convey some idea of Ins personality and his work.

This occasion will not permit an exhaustive analysis of his scientific
work. I shall hope at another time to treat of that more fully. I will
only call your attention to the prominent traits of his personal character,
and to some of the epochs of his professional career.

Alexander Winchell was born in the town of Northeast, Dutchess
county, New York, December 31st, 1824. He died at Ann Arbor, Michi-
gan, February 19th, 1891.

His work was many-sided and voluminous. Asa youth and young
man, he excelled in mathematics and had a leaning toward civil engi-
neering and astronomy as a field for his life's energies. This facility of
mathematical reasoning has given cast to some of his later philosophi-
cal speculations, in which his arguments are connected and expressed
in algebraic form. Later he spent two years at South bee. Massachu-
setts, with a venerated uncle, a leading physician of Berkshire county,
making preliminary preparations for the medical profession. Aboul this
time also his parents and some of his trusted advisers urged upon
him the Christian ministry. These early inclinations had their effect on
his Later Life, and appear prominently in his predilections for physiologi-
cal and fcheologico-scientific writing. He delighted in music and poetry

4 PROCEEDINGS OF WASHINGTON MEETING.

and sculpture : and his keen esthetic taste, united with a ready appre-
hension of esthetic truth and a lively imagination, have produced a large
mass of exquisite poetic composition, never published, or but partially
published. He became, a1 Ann Arbor, a patron and an influential pro-
moter of the musical interests of the city and of the university, having
served for several years prior to his death as president of the University
Musical Society. He had a quickness of perception of physical form,
and a deftness in mechanical construction. These resulted in some
modeling in plasterof Paris, as well as in many hand-sketches and draw-
ings. To his college training in Latin and Greek, he added Hebrew,
German and French; and later, along with Spanish, he also acquired a
sufficient knowledge of the Scandinavian to enable him to read the
scientific works in which he was concerned in these languages.

The fortunes of his birth not having afforded him the means and
opportunity to devote himself at once and uninterruptedly to any
chosen line of professional labor, he resorted to teaching as a double
means of financial revenue and of personal improvement. In this he
was rapidly promoted ; but this rapid promotion was due more to his
scholarship and his success as a leader of his best pupils than to any
personal magnetism or sympathy which he inspired in his classes as a
whole. He had no care for laggards, and only a passing regard for the
indifferent or mediocre; but for the student who manifested a special
earnestness, or exhibited more than a casual interest in natural science,
he was ready to spend any amount of extra time and to render unsel-
fishly any service that might be required. He passed rapidly through
the lower grades of the teacher's profession to that of a full professor in
tin' department of science which he had chosen. The teaching pro-
fession brought him frequently upon the lecture platform, and his
earnest interest in the educational and social issues of the day, as
brought out in the leading periodicals, prompted him to participate in
the discussion of them. As his contributions on the issues of scientific
instruction and scriptural interpretation always bore the impress of
Christian faith and of scientific as well as philosophical acumen, he
was marked as a defender of the Christian church against assaults
which scientific men had made upon it. These qualifications, admired
by the scientist no less than by the Christian educator, recommended
him for still higher promotion, and he was elected and inaugurated as
chancellor of Syracuse university, at Syracuse. New York.

He soon discovered, however, that the financial and other vexatious
details of university administration absorbed all his energies, and as
there was no likelihood of relief, he, contrary to his expectation when
he accepted the position, promptly resigned and accepted again a pro-

MEMORIAL OF ALEXANDER WINCHELL. 5

fessorship in the same institution. It was during his residence at
Syracuse that were laid the first lines of an episode in his professional
career which was to become the most distinctive event of his life. He
gave by invitation a series of papers in the Northern Christian Advocate
on " Adamites and pre- Adamites," which were published in pamphlet
form. This had been preceded by a lecture on the same subject before
the Bible class of the Methodist church at Syracuse, and was followed
by an article on " Pre- Adamites " in McCTintock and Strong's encyclo-
pedia. In this he singled out the Noachian descendants as of later
origin than several other branches of the human family, and, without
contravening any of the statements of divine scriptures, attempted to
show wherein some of their current interpretations ought to be corrected.
The whole effort was one of those far-reaching expositions of scriptural
and scientific harmony for which he was becoming famous, and which
only required for their universal acceptance the abandonment or modi-
fication of some dogmas of human origin. He had been lecturing on
geology four years, at Vanderbilt university, at first dividing his time
between that institution and Syracuse university ; but these views were
supposed by the authorities of Vanderbilt to be heretical, and when he
refused to decline a re-appointment in May, 1878, the lectureship which
he held there was unceremoniously abolished. This act, which flavored
of the proscriptions of the middle ages, created a profound sensation in
educational circles. He received such a spontaneous and instant sym-
pathy and support that, smarting under the injustice of trial and con-
viction and punishment without the opportunity of defense, he elabo-
rated the work of the pamphlet on " Adamites and pre-Adamites " into
an attractive volume of five hundred pages, which was published in
1880. This volume may be taken as the type of a large number of
publications, partly theological and scriptural and partly scientific.
which won for him the respect and confidence not only of numerous
scientific students but also of many churchmen, and which have
served to allay the fears of many as to the attitude of scientific men
generally toward Christianity.

On his return to the university of Michigan in 187!>, he resumed
more strictly scientific work ; but the multiplied demands made upon
him for scientific contributions of a more popular character interfered
seriously with his plans. Within the first three years appeared not
only his " Pre- Adamites," but "Sparks from a Geologist's Hammer"
and " World Life." On the Last he spent more time than on any of his
former publications. It is an amplified reproduction of principles and
discussions which he had presented in more or less fragmentary form
in public lectures during several years, and tills the place in the realm

6 PROCEEDINGS OF WASHINGTON MEETING.

of physical science in its relation to the Christian faith which the
" Pre- Adamites " fills in the realm of anthropology. In rapid succession
followed '" Geological Excursions ; " " Geological Studies, or Elements of
Geology " (1886) ; "Walks and Talks in the Geological Field " (1886),
•Shall we teach Geology?;" and three annual contributions to the
reports of the Geological Survey of Minnesota, the last of which, '"Amer-
ican Opinion on the Older Rocks,*1 reached him in printed form but a
few weeks prior to his death.

This is the merest skeleton-sketch of the busy life and fertile pen of
Alexander Winchell. It takes no note of his daily labors in the class-
room, nor of his minor papers, some of which are lengthy and involved
the severest study, nor of his technical geological work as director of the
geological survey of Michigan. This was all interspersed again with
public addresses at commencements, and platform lectures in nearly all
parts of the United States. No one can give attention to the multiplicity
of the avenues of his labor without experiencing a profound conviction
of his untiring industry and versatility, and at the same time of the
breadth and depth of his intellectual capacities.

The full number of his literary compositions published, according io
a list kept by himself, is live hundred and sixty-six. He described seven
new genera and three hundred and four new species of organisms, mostly
fossil, and sixteen neAv species were named for him by other paleontolo-
gists. There remain unpublished numerous poems, minor manuscripts
and journals, and the larger part of a volume on ik Intellect and Religion,"
as well as an uncompleted memoir for the United States Geological Sur-
vey on Carboniferous and Devonian fossils — an amplification of his work
on the "Marshall group" based on his collections for the Michigan
geological survey and on other collections made later.

It is evident to the most casual observer who considers the volume and
variety of his literary work, that lie was a man of strong personality
and that he was dominated by the strongest convictions. The firmness
and the depth of all his mental movements were equalled only
by their enduring constancy and their untiring activity. He was
from boyhood physically strong, and in his manhood he was rarely
interrupted by bodily ailment. The stealthy disease (aortic stenosis)
which finally surprised him and us was probably upon him for
many years, but it did not prostrate him nor even incapacitate
him for more than a few days. He was in the midst of a popular
course of lectures before the geological society of the university
of Michigan : three had been given on " Evolution," but the fourth
and last, which was specially entitled " Philosophy of evolution."1

MEMORIAL OF ALEXANDER WINCHELL. I

was temporarily postponed, owing to increasing debility and the direct
advice of his physician. It was to have been given February 6. On
the small-page hand memorandum containing the catch-words of the
argument of each lecture, from which he elaborated his theme extempo-
raneously, and which was found on his desk after his funeral, he had, in
pencil, inserted an arrow-point denoting the place at which the course
was interrupted. This being absolutely his latest public work, it has
a melancholy interest and value, and the entire page is here appended :

Evolution.

Its principles and proofs, popularly discussed in four lectures, under the
auspices of the Geological Society of the University of Michigan.

Jan. 16. — World Evolution.

The method of world-origin, world-growth, and world-decay ; the
same for all worlds. The spectacle of the universe, unity of method,
and unity of creative intelligence. Divine plans and basis of inter-
communication among the populations of all worlds. Evolution the
unifying conception.

Jan. 23. — Organic Evolution.

I. The March of Extinct Life- — The method of its march through the
ages. The germinal conceptions evolved in time. The vertebrate type
in its secular expansion- Advent of man. His organic evolution past
its culmination. Man the subject of psychic evolution. Commence-
ment of physical decadence.

Jan. 30. — Organic Evolution.

II. Heredity and Variability. — Conditions of variability. Environ-
ment and adaptation. Examples of variation.

III. Morphological Evidences. — Family resemblances. Blood resem-
blances. Visible kinships among animals. Common descent.

IV. Embryological Data. — Parallelism of embryonic histories. Par-
allelism with gradations of animals. Parallelism with paleontological
succession. The three parallels illustrated by a diagram.

Feb. 6. — Philosophy of Evolution.

What is Darwinism? Misapprehension of causation. Relation to
environment conditional ; not casual. Cause acts now and here. The
efficient cause in the organism. The efficient cause immaterial. The
efficient cause discerning. Evolution reveals the universe as one em-
pire; establishes the unity of creative intelligence; and proves human
kinship with the infinite mind.

To these lectures such Large numbers of auditors, both students and
citizens, Hocked that they were driven from the room which was his

8 PROCEEDINGS OF WASHINGTON MEETING.

Lecture room, first into the law lecture room, and then into the general
assembly hall of the university, where it was estimated that from
twelve hundred to fifteen hundred listeners waited and were instructed
for an hour and a quarter on the occasion of his third lecture. This
was the last time he was outside of his home, and he was so weak that
some friendly students literally bore him to the carriage which was wait-
ing to convey him back.

He certainly expected to recover so as to be able to deliver the final
lecture of the course, though evidently there were misgivings — misgivings
whose shadowed presence in his calculations for some months previous
can be read from small acts and sayings which are now recalled, but
which at the time attracted but little attention.

After he had definitely chosen as the arena in which he should work
out his professional career and had been appointed to teach the natural
sciences, there are distinctly two epochs in his life which are separated
from each other by an important official event. The first epoch is that
which is marked by his devotion to rigorous scientific investigation, the
discovery of the unknown. The second epoch isthatmarked by his broader
grasp of things already known in science, and his classification of the known
into system. It will not be correct to suppose that he wholly abandoned
one when he took up the other, or that he did not already labor in the
latter before he gave up the former ; for throughout his life he was ready
to engage, and did engage, in either as opportunity was presented. Still,
he did himself make announcement of this transition from the special to
the general in his scientific labor. This distinction and division were
instituted by his giving up of the geological survey of Michigan and
abandonment of all hope of future work in that direction, and were
accentuated later by his acceptance of the chancellorship of the Syracuse
university. The war of the Rebellion interrupted the Michigan survey
in 1861, after two years of successful field and laboratory work. The
official result of these two years is embraced in a volume of 339 pages,
printed in 1861* But the most valuable results appeared unofficially
in later publications, chiefly in the proceedings of the Academy of
Natural Science of Philadelphia, the American Journal of Science, and
the proceedings of the American Philosophical Society. During the eight
years that elapsed before the survey was revived (1869) he was mainly
engaged, so far as strictly geological work was concerned, in elaborating
its paleontological results and in special surveys of limited districts with
special reference to their economic resources. Thus he became familiar
with the geological conditions of the salt and petroleum rocks of Michi-

* First Biennial Report of Progress of the Geological Survey of Michigan: Lansing, 1861,

MEMORIAL OF ALEXANDER WINCHELL. 9

gan, Ohio and Canada, on which he made special studies. In respect
to the salt-hearing strata of Michigan he established the basin-shaped
form of the strata, and defined not only the principles but also the geo-
graphic area in which brine might be found. His chief geological problem,
however, during this interim was the establishment and defense of the
" Marshall group," which on paleontological, historical, and stratigraphic
evidence comprises a great series of Subcarboniferous strata which, as a
body, belong together, although they had in part been embraced severally
under the names Catskill, Waverly, Kinderhook, Goniatite limestone >
Yellow sandstone, Chouteau limestone, and Siliceous group*

On the resumption of the survey in 1869, he was chosen director by
the geological board and entered upon his duties with great zest. The
eight years that had passed since it was interrupted had broadened his
views and qualified him, by his more extended acquaintance with the
state and with its geology as well as with the geology of adjoining states,
to carry on the survey rapidly and effectively. Preparatory to the
meeting of the state legislature he drew up a report of progressf and had
put into print a plan for his final report. Unhappily, complications of
personal and political nature arose and threatened the success of the
survey, and my brother resigned his commission.]: The geological board
never appointed a successor but parcelled out the survey to different
geologists ; and their separate reports, conceived and prepared in accord-
ance with the plans of the director, were subsequently published as
official reports on the geology of the state.

Thus my brother was turned from his chosen field of special geological
research and led into the broader domain of systematic study, un-
doubtedly to the loss of the citizens of Michigan but to the benefit of the
wider circle of readers of his later writings.

We do not, however, enter within the domain of Alexander Winchell's
greatest achievements until we consider his broader discussions of the
relations of modern science to education, to culture, and to Christian faith,
and his contributions to natural theology. He imbibed from his boy-
hood training a profound reverence for the holy scriptures, and his whole
life was a testimony, no less in its daily manifestations than in its con-
secration to correct biblical interpretation, to his belief in their teach-
ings. While he accepted and defended the integrity of the Christian
faith, he insisted with equal pertinacity that Christian faith must have

• The Marshal] Group: A memoir on its Geological Position, Characters and Equivalents in the
United states. Proceedings Am. Phil. Soc, vols, xi and xii. L869 ami 1870.

t Report mi tin- Progress of the State Geological Survey <>t' Michigan, Presented t" the Geological
Board Nov., 1870: Lansing, 1871. mm, i;i pp.

I The circumstances which led to the resignation arc caricatured in " Sparks from a Geologist's
Hammer" under the allegory ".V remarkable Maori manuscript."

II— Bull. Geol, Soc. Am., Vol. 3, 1891.

10 PROCEEDINGS OF WASHINGTON MEETING.

and does have a rational foundation and sanction in human reason ; and
lie ascribed the conflicts between science and religion which have been
insisted on both by Christian theologians and by atheists to wrong ideas
of the relations that subsist between them and to dogmatic interpreta-
tions and traditions — or else to the weakness of the light which reason
has been able to derive from the flickering flame of science, or from
the glare of profane history. His position among the scientists of
America in this respect was sometimes bold and often unique. His
earliest scientific thinking and his first public addresses were cast in a
mold of theistic faith. Although the mold was compelled to grow through
various enlargements and modifications, it was never thrown aside.
Thus, in 1857, he addressed a bible class at Ann Arbor on " Theologico-
geology, or the teachings of scripture illustrated by the conformation of
the earth's crust; " and in 1858 his final lecture of a course before the
Young Men's Literary Association of Ann Arbor, was entitled " Creation,
the work of one intelligence and not the product of physical forces."
His hesitancy in the adoption of evolution as the method of organic de-
velopment of species continued only so long as he was unable to give it
sufficient examination to define its bearings on his conception of divine
agency in creation. His small work, " The Doctrine of Evolution ; its
Data, its Principles, its Speculations, and its Theistic Bearings " (1874),
was the result of that preliminary examination. He sat down to the
task with an expectation to reach an adverse conclusion. He rose from
it satisfied of its theistic basis — the panurgic energy of evolution is the di-
vine intelligent will, the single synthetic force of which all other forces of
matter are but specialized forms. This central conception once estab-
lished, it was his delight, as evinced in hundreds of lectures and in all
his later publications, to group the phenomena of physical and organic
nature about it, and to reenfore it by all the eloquence and philosophy
and learning which he could command. It was the central conception
and the designed finale of that last course of lectures from which death
snatched him away. *

In scientific education he bore a conspicuous and burdensome part.
Going to the university of Michigan in 1854, he found a young state
institution in a crude state of organization and without anv definite
recognition of the natural sciences as factors of culture and as necessary
elements in a college curriculum. He went energetically to work to

* He was advised by many during the past two years to issue a revised edition of his " Doctrine
of Evolution," but he steadily declined, for he had in mind the publication of a thorough treatise
on evolution as a sequel to that work. He considered his "Doctrine of Evolution" as a sort of
court trial of the cause of evolution by a judicial and impartial mind. That trial concluding with a
verdict favorable to evolution, he wished to himself take the position of an advocate and to prepare
its strongest affirmative argument.

MEMORIAL OF ALEXANDER WINCHELL. 11

influence public opinion. He was conspicuous in the State Teachers'
Association, of which he was soon elected president. He wrote numerous
reports and appeals and resolutions, and in 1858 he was charged with
the editorship of the Michigan Journal of Education, which, with great
tact and distinguished ability, he made to tell the story of the natural
sciences and to plead for scientific instruction in all the schools. His
objective point was to introduce natural science in a systematic manner
into the secondary schools of the state, and through them to feed the
state university with a class of students that would expect and demand
a higher grade of scientific instruction from that institution. He never
wearied in this effort, some of his latest publications (e. g., " Shall we
Teach Geology ? ", 1889) voicing the same plaint in louder and more
immediate appeals. He urged the university authorities, who to him
manifested a lethargic indifference, to consider the needs of the institu-
tion in this particular, to plan for greater facilities for teaching the sciences,
and to build up greater attractions to the student scientifically inclined.
He pointed, with a tinge of humiliation, to the newer institutions of like
grade further westward which have outstripped the university of Michi-
gan in scientific appliances, having caught the moving spirit of the times
and having made provision for a future career in natural science which
has yet to be entered upon at Ann Arbor. " That, also, goes for nothing,"
said he, not ten days before his death, as he sorrowfully pointed to some
rejected plans for a new science hall at Ann Arbor, which had been
devised jointly and had been {presented unsuccessfully to the authorities
of the university. I understood that the legislature, then in session,
had not been asked to make provision for it in the stated appropriations.
Future years, however, will reveal to the people of Michigan, and espe-
cially to the regents of the university, the great difficulties with which
ho had to contend, and they will hasten to repair the great defect which
his sagacity pointed out and which his labor aimed to remedy.

Cognate with his efforts to build up directly a scheme of higher
scientific instruction in the schools were his efforts to popularize science
among the citizens at large. His work " Sketches of Creation " (1870)
has had an enormous sale. It proves the eagerness of the enlightened
American citizen to penetrate, albeit not through the avenues of technical
science, into the recesses of profound scientific truth and imagination.
One of flu' greatest services which lie rendered to geology was to clothe
its great truths in attractive words adapted to the masses. The thousands
who have read " Sketches of Creation " or " Walks and Talks in the Geolog-
ical Field," will, should occasion arrive, testify to the cultural as well as the
economical value of geology. Such occasions arise annually in the
state legislatures and in our educational hoards, and no one can esti-
mate the influence which his beautiful popular essays have had in

12 PROCEEDINGS OF WASHINGTON MEETING.

bringing about the present multiplicity of geological surveys and open-
ing the avenues to favorable legislation by the states of the Union and
by the United States congress.

Time will not permit me to enter upon a special study of his separate
publications, however inviting and profitable it might promise. We can
here only sketch some of the grander steps of his life, and bear our tribute
to his goodness, his untiring industry, and his single-minded consecration
to the truth. As geologists we have to acknowledge ourselves deeply in-
debted to him ; for he explored in advance of us some of the deepest and
darkest recesses of our science ; he scanned the heavens of all science and
all philosophy, and he brought forth new things and classified old facts
which before had been chaotic or contradictory. His imagination served
him as a scientific guide to unknown realms ; his language clothed his
descriptions with beauty and his ideas with definiteness and reasonable-
ness. As a rhetorician few have excelled him ; as a popular scientific
expositor, and especially as the harmonizer of apparently conflicting
truths in science and religion, none have equalled him. He constructed
an arch and put in the keystone connecting two independent pillars of
truth. He was able to stand and to work on either of these pillars ; and,
being so able, he saw that they were designed to sustain the same great
superstructure. The pillars are revealed truth and natural truth, and
the superstructure is the unison and harmony of all truth.

My duty would not all be done did I not refer to his relations to this
Society, and his agency in effecting its successful organization. He was
among the first to see the need of this organization, and cooperated with
the preliminary committees. The Society, however, as an actuality,
made but little headway until the Cleveland meeting, where he was made
the presiding officer ; and by his judicious selection of committees and
the drafting of a preliminary constitution the Society was formally
organized, and a large number of influential geologists then present
signed the preliminary articles. Since then he has been uninterruptedly
in the service of the Society. He has attended every meeting of the
Council and every meeting of the Society, having presided, in whole or in
part, at every meeting of the latter. Our constitution was drawn up by
him in the first instance. It is not too much to say that if to any one
belongs the title of " Father of the Geological Society of America," it is
to Alexander Winchell. The Society, therefore, to-day for the first time
draped in mourning, has lost not only its present chief officer but its
strongest friend and promoter.

In conclusion : We cannot now fully realize the loss which the death
of such a geologist inflicts on the science of geology in America. He was

MEMORIAL OF ALEXANDER WINCHELL. 13

not all the time active in the fighting camp of the fray, but he was always
in the great contest. He was organizing the forces, and laying far-reach-
ing plans for campaigns which the future alone will work out ; he was
rallying the reserves by public enlightenment on the issues and utility
of all science. He increased our friends and disarmed our foes. He
propitiated many who were hostile or indifferent. His influence was
felt where it was little suspected. The next generation, scanning the
history of the present, will detect the agency which he bore out in the
scientific and particularly in the geologic movements of this, and the
next century can best point out the men who, in the closing years of the
nineteenth century, bore the great burdens and discharged the great
functions on which the progress of truth and the increasing happiness of
man depend.

Following the reading of the memorial, it was moved by Professor
Charles R. Van Hise and unanimously voted that a special committee
of three be appointed to prepare and submit to the Society resolutions
in expression of the sentiments of the Society regarding the death of
President Winchell. The chair appointed as such committee Edward
Orton, Charles A. White, Charles R. Van Hise*

No reports of committees were presented and no miscellaneous business
was offered. After announcements regarding the sessions of the Society
and of the approaching International Geological Congress, Acting Presi-
dent Gilbert declared the scientific work of the meeting in order, and
announced the first paper upon the printed program :

A GEOLOGICAL MAP OF SOUTH AMERICA.

BY PROP. DR. GUSTAV STEINMANN, OF THE UNIVERSITY OF FREIBURG, GERMANY.

(Abstract.)

This geological map of South America forms a part of the geological section of the
" Physikalischer Atlas von Berghaus" (Gotha: J.Perthes). There are many re-
semblances which have existed between the two Americas up from Paleozoic time.
So the Devonian fauna of Bolivia connects the North American faunas of that age
with those of Brazil, Falkland islands, and South Africa. In both regions, during t lie
Triassic and Jurassic periods, marine deposits were not formed on the greater part
of the continent, hut at the commencement of the ( Iretaceous period large areas were
covered by the sea, especially in the northern pari of South America i Brazil, Colom-
bia, Venezuela, etc. ) and in the southern part of North America Mexico, Texas, etc. .
In southern Chile there exists a continuous series, partly of Cretaceous and partly of
Tertiary age, w hich seems to be analogous to the ( !hico-Tejon group of ( 'alifm'nia.

* TI h • resolutions appear in the proceedings of Augusl

14 PROCEEDINGS OF WASHINGTON MEETING.

The glacial deposits seem to have a much greater extent in South America than
has been supposed. In the Cordillera of Capiajo moraines are found at a height of
about 1,200 meters above sea level, and Raimondi, twenty years ago, described the
same deposits from the department of Ancachs, in Peru (about (.»° south latitude),
reaching down to about 2,500 meters above sea level. These facts merit our atten-
tion with regard to the theory concerning the alteration of the terrestrial axis or
the contemporaneity of the glacial periods on both hemispheres.

The paper was discussed by E. D. Cope, R. T. Hill, and C. A. White.
Mr. Hill thought there would probably be found some correspondence
between the Cretaceous of the western coast of South America and that
of the United States. Dr. White spoke as follows :

My own investigations with relation to South American geology, to which Dr.
Steinmann has referred, have been confined to the Cretaceous invertebrates of Brazil.
When studying the fauna, which was collected by members of the survey under
Professor Hartt and sent to me for that purpose, I was not able to identify a single
species with any North American form. Neither was I able to detect any close
affinity between the Brazilian fauna and that of any North American formation.
On the contrary, I found that a considerable number of the Brazilian forms were
closely like a part of the Cretaceous fauna of southern India, and some of the
species 1 treated as being identical. I was not then, and am not now, able to say
that all the species which were sent to me came from one and the same stage of
the Cretaceous series. If they did, there is certainly a remarkable commingling of
earlier and later Cretaceous types. I do not think such a commingling is improb-
able, and I therefore treated the collections sent to me as a faunal unit, and in sum-
ming up all its characteristics I referred it to the Neocomian.

In reply to questions Dr. Steinmann said that enormous beds of
eruptive material were found between thin bands of limestone ; that
continuous eruptions of all kinds of volcanic rocks took place in the
Chilean cordillera during Jurassic and Cretaceous time. In eastern Brazil
there is conformity between the Carboniferous and the lower Cretaceous,
which rests upon the former. The Paleozoic rocks are metamorphosed ;
the later are not.

The full paper is printed in the American Naturalist, vol. xxv, 1891,
pp. 855-800.

The next paper was entitled—

ON THE PERMIAN, TRIASSIC, AND JURASSIC FORMATIONS IX THE EAST INDIAN

ARCHIPELAGO (TIMOR AND ROTTl).

13Y DR. AUGUST ROTIIPLETZ, OF THE UNIVERSITY OF MUNICH, GERMANY.

In discussing this paper Dr. C. A. White remarked :

The paper which has just been read by Dr. Rothpletz is of peculiar interest to me
because some late studies of mine in Texas are of a similar character. These dis-
coveries in their essential character are similar to those of Waagen in India,

DISCUSSION BY C. A. WHITE AND L. F. WARD. 15

Karpinsky in Russia, and Gemmellaro in Sicily. They show that a large proportion
of the faunal types which have long heen regarded so characteristic of the Mesozoic
began their existence before the close of Paleozoic time, and that these forms often
constituted members of faunas which embraced well-known Carboniferous species.
They also show, what we ought always to have expected to find, that upon the
confines of systems and formations there was necessarily a faunal gradation from
the earlier to the later divisions.

Professor Lester F. Ward spoke as follows :

I am glad to observe that the invertebrate and vertebrate paleontologists are be-
ginning to discover that the evidence of the fauna relative to the age of the deposits
of the southern hemisphere is not as harmonious as was originally supp< ised. With
regard to the plants, we are not of course as yet in condition to make any very broad
generalizations, but we have at least reached a point where we can propose a
hypothesis which, however much it may require to be modified, is certain to lead in
the direction of ultimate truth. This hypothesis is briefly this : At an early period
in geologic history there flourished in both hemispheres a vegetation which is
commonly understood as the Carboniferous flora, consisting of the lepidophytes,
calamites, and marattiaeeous tree-ferns, together with the genus Cordaites, alone
representing the phanerogams. In the southern hemisphere, in addition to this
Carboniferous flora and contemporaneous with it, there existed another and quite
different type of vegetation which we now call the Glossopteris flora. When the
great Permian glaciation of those regions came on, the true Carboniferous flora proved
incapable of supporting the lowered temperatures and succumbed. The Glossopteris
flora, on the contrary, consisting largely of the primordial representatives of higher
types of vegetation — cycadaceae, conifers, etc. — survived, persisted, and underwent
great modification. In its modified form it came at length to constitute the now
well-known Mesozoic flora of Australia and India, the types of which can be traced
back into the Paleozoic. This Mesozoic flora of the southern hemisphere, already
found in southern Africa and in South America, which also contain true Glossopteris
types, not only persisted long in these regions but migrated northward and is now
found, altered it is true but distinctly recognizable, throughout vast areas of the
northern hemisphere. From India it found its way to Cochin-China, China proper,
and Japan, as also to Persia, Asia Minor, and the Caucasus. In South America it occurs
in the Argentine Republic and Chile ; it also reappears in the state of Honduras and
in Mexico, both in the central part and also in Sonora along the Rio Grande. From
the last-nan led locality, and probably as an eastern extension of the same area, we
find it occupying the great arid plains of Arizona and New Mexico— the Shinarump
formation of Powell. It again conies forth along the Atlantic slope in the; Con-
necticut valley, in New Jersey, Pennsylvania and Maryland, and on southward
through the coal fields of Virginia and North Carolina. In Europe it is this same
greal .Mesozoic flora which has been so abundantly exhumed and brought to light
in Franconia (Bavaria), in Brunswick, in southern Sweden, and in many parts of
France, while to it also belong the celebrated upper Triassic beds of Raibl in ( larin-
thia,of l.uu/. in Austria, of Stuttgart in Wurtemberg, and of Nine Welt near Basle
in Switzerland. However much these floras may differ specifically, they all have

the same general Eacies, and bear evidence of having descended with modification

from the original Glossopteris flora of Carboniferous age, which must then have
covered land areas in the far south much greater than those of I lie present day.

This paper will be published in the American Naturalist.

16 PROCEEDINGS OF WASHINGTON MEETING.

The following paper was then read :

THERMOMETAMORPHISM IN IGNEOUS ROCKS.

-'c

BY ALFRED MARKER, M. A., F. G. S., OF ST. JOHNS COLLEGE, CAMBRIDGE, ENGLAND.

The metamorphic effects due to the heat of intruded masses have, from the days
of Hutton, received a fair share of attention from geologists, and as regards the
phenomena thus induced in various types of sedimentary rocks we are now in
possession of a considerable array of facts. Observations on the thermometamor-
phism of igneous rocks and of crystalline schists are, however, very few, despite
the fact that any such investigation might be expected to throw light on some
problems prominent in modern geology. So far as the crystalline schists are con-
cerned, indeed, the field is almost unbroken, though such researches as those of
Professor G. H. Williams in the Cortland district and of Salomon in the Adamello
range have shown it to be a very promising one. In this place I confine myself to
some of the facts already ascertained with regard to thermometamorphism in nor-
mal igneous rocks.

The earliest contribution of importance is that of Allport * who drew attention
to the uraliti/ation of the augite in the " greenstones " adjacent to granite intru-
sions in Cornwall. Lessen f described similar effects in the diabases of the Harz,
and more recently Dalmar, j Sauer,§ and Beck || have found diabases converted into
actinolite and anthophyllite schists around the syenite of Meissen, etc, in Saxony.
All these observations refer to the modifications set up in one family of rocks.
Barrois' *[ " diorites," metamorphosed by the Rostrenan granite in Brittany, appear
also to have been originally pyroxenic rocks, though the uralitization is not entirely
confined to the vicinity of the contact. In the diabases and diorites of the Macon-
nais and Beaujolais, metamorphosed by irruptions of microgranulite, Michel Levy **
has described somewhat different phenomena, including the " epigenesis of labra-
dorite crystals by the microgranulitic magma." So far the acid irruptives have
received no notice, and the same may be said, except for a few remarks by Judd,ff
of the whole of the volcanic division. It is with the last-named rocks that I pro-
pose to deal in this communication.

For a study of thermometamorphism in volcanic rocks there can be no more
instructive field than the English Lake district. All the central part of that dis-
trict is occupied by a great volcanic series of Ordovician age, consisting of both lavas
and fragmental accumulations ; and at certain places on the edge of the district
these rocks all come within the metamorphosing influence of large igneous intru-
sions.

The lavas belong to three distinct petrographic gi*oups, presenting, despite their
geological antiquity, all the characteristics of the volcanic habitus — the fluxional
arrangement of their elements, the vesicular structure, the development of porphy-
ritic crystals, and (subject to secondary modifications) the isotropic residue. There

♦Quart. Journ. Geol. Soc, vol. xxxii, 1876, p. 418.

fErlaut. zur geol. Speeialk. Preuss., Blatt Harzgerode, 1882, pp. 79, etc.

X Erlaut. zur Speeialk. Konigr. Sachsen, Section Tanneberg, 1889, Blatt 64.

I Ibid. Section Meissen, 1889, Blatt 48.

I! Zeits. deuts. geol. Ges., vol. xliii, 1891, p. 257.

If Ann. Soc. Geol. Nord, vol. xii, 1885, p. 1U2.

**Bull. Soc. Geol. Fr., ser. 3, vol. xi, 1883, p. 29C.

ff Quart. Journ. Geol. Soc, vol. xlvi, 1890, p. 370.

A. HARKER — THERMOMETAMORPHISM. 17

are 1 1) basic lavas (hypersthene-basalts) with about 51 per cent of silica, characterized
by basic feldspars, hypersthene, and iron ores, but without olivine ; (2) intermediate
lavas (pyroxene-andesites) with 59 per cent of silica, some containing a monoclinic,
some a rhombic pyroxene, and some both ; (3) acid lavas (rhyolites) with 75 per
cent of silica, showing various phases of the glassy type, with feeble porphyritic
development and a strong tendency to microspherulitic and macrospherulitic
structures. These acid lavas, in which the ferromagnesian minerals are almost
completely wanting, bear a close resemblance to certain American Tertiary rhyo-
lites, such as those described by Mr. Whitman Cross from Custer county, Colorado ;
and the other types of Lake district lavas are not difficult to parallel among the
newer volcanic rocks of the United States and central Europe.

The fragmental igneous rocks of the English Lake district, varying from fine
submarine ashes to coarser breccias and agglomerates, are associated with each of
the three groups of lavas. Those belonging to the acid group are chemically similar
to the rhyolites themselves, and are not always easily distinguished from them in
the field. The ashes and breccias associated with the intermediate and basic groups
are often more acid than the lavas, owing to the inclusion of numerous rhyolite
fragments. All the fragmental rocks, though of subaqueous formation, are in
general of purely volcanic origin ; but some of the rhyolitic ashes and breccias in
the upper part of the series (which passes up into the Coniston limestone group)
contain a variable admixture of foreign material, both detrital and calcareous.

On the western side of the district the volcanic rocks are in contact with extensive
intruded masses — the granophyre of Buttermere and Ennerdale and the granite
(often granophyric also) of Wastdale and Eskdale, — and extreme metamorphism
has been set up. The same phenomena are presented in equal variety and with
greater clearness in the neighborhood of the granite of Shap fell on the eastern
edge of the district. Here, too, ordinary sediments, calcareous, argillaceous and
arenaceous, come within the same metamorphosing influence, and afford a standard
of comparison for the effects produced in the volcanic rocks. It may be remarkedj
also, that the district offers an admirable field for the study of dynamometamor-
phism in the same rocks and for comparison of the two lines of modification which,
as here developed, give rise to widely different phenomena. The Shap fell tract
in particular has been carefully examined by Mr. J. E. Marr and myself. Details
of field-work and chemical and microscopic study would be out of place here, and
have been recently published elsewhere ; * but the results give occasion for some
remarks bearing on thermometamorphisrn as a whole, and thus possessing a general
interest.

The metamorphic aureola of Shap fell extends for about three-quarters of a mile
from the visible granite outcrop, and this distance is nearly the same whether we
take it in the volcanics or in any of the sedimentary groups. In this connection,
however, it should be noted that the volcanic rocks had undergone considerable
alteration by meteoric agencies prior to the intrusion of the granite, which took
place in post-Silurian times. Such evidence as we have goes to show that fresh
volcanic rocks would be less readily affected by thermometamorphisin. At the
outer edge of the aureola it is only the decomposition products of the intermediate
and basic rocks that have been transformed; similarly in the sedimentaries it is
the calcite, carbonaceous matter, etc. The general rule seems to be that the sub-

* Quart. Journ. Geol. Soc, vol. xlvii, 1891, p. 266.
I I— Bull. Geol. Soc. Am., Vol. 3, 1891.

18 PROCEEDINGS OF WASHINGTON MEETING.

stances most susceptible to thermal agency are those formed under ordinary me-
teoric conditions, minerals of direct igneous origin being more refractory.

The outer limit of the aureola, as denned by the production of new minerals
undoubtedly due to the metamorphism, is fairly well defined. From there to the
granite contact the metamorphism increases progressively, affecting at last all the
constituents of the rocks, so that near the granite they are, with special exceptions,
completely reconstituted. The changes in character from the outer to the inner
limit are so gradual as to render futile any attempt to divide the aureola into suc-
cessive distinct zones. The boundary against the granite is always a perfectly sharp
one.

An important problem in connection with thermometamorphism is how far, if
at all, are the transformed rocks altered in total chemical composition. It would
be rash to give a general answer to this question without much more extensive
chemical researches than any yet undertaken ; but there are some facts which throw
light on the subject. It is worth remarking, too, that for this purpose igneous rocks
present advantages over sedimentary, in virtue of their more homogeneous nature.
It is not safe to assume that a mass of slates was originally of one chemical compo-
sition throughout, but this difficulty scarcely arises when we can trace a lava flow
from beyond the limit of the aureola up to its contact with the intrusive rock. The
rocks examined decidedly favor the view that thermal metamorphism is not in
general accompanied by any change in bulk analysis. Two exceptions must be
recognized. The first consists in the elimination of the volatile constituents of the
rocks metamorphosed, viz, water and carbonic acid. The loss of the water, how-
ever, does not seem to be complete, hydrous minerals, such as certain micas, often
occurring in highly metamorphosed rocks ; while the expulsion of the carbonic acid
depends on the presence of silica, free or combined, to take its place, for we find
that such expulsion does not operate in the case of a pure limestone. The second
exception to the rule consists in the introduction in some cases of certain volatile
constituents, such as fluorine and boric acid, and must be referred to the " mineral-
izing agents " on which some French geologists have laid stress as necessary con-
comitants of an acid intrusion. There is, however, but little trace of these among
the Lake district rocks. Tourmaline occurs very sparingly at Shap fell, always
close to the granite and always in immediate connection with old joint planes or
other fissures, and muscovite is found mostly under similar conditions. Axinite
and fluorite are not known.

In some described cases of thermometamorphism it has been considered that the
altered rocks have, in the neighborhood of the contact, received an accession of silica
derived from the invading magma. No such process can be verified in the Lake
district. Some of the rocks, and especially the rhyolitic lavas and ashes, have un-
doubtedly been impregnated with silica, and a similar feature is not uncommon in
the acid lavas of northern Wales and other districts. The silica is sometimes seen, in
slices, to have replaced feldspar crystals, and the abnormally high silica percentage
in some analyses of old rhyolites must be explained by some such secondary action.
But the phenomenon in question has clearly no relation to subsequent igneous
intrusions, occurring, as it does, often in places far remote from any intruded mass.
Whether due to ordinary meteoric weathering or, as seems probable, to solfataric
action not long posterior to the cessation of vulcanicity, this silicification cannot be
referred to any cause properly described as thermometamorphism.

A. HARKER THERMOMETAMORPHISM. 19

In the metamorphism characteristic of the Lake district, the chemical changes
involved in the production of the new minerals are of various degrees of complexity.
There may be simple paramorphism, as when chalcedonic silica filling cracks in
the lavas is converted into crystalline quartz, still retaining in some cases its char-
acteristic mammillary structure. There may be mere dehydration, as perhaps in
the almost universal formation of brown mica from the chloritic decomposition
products of pyroxene, etc. To convert a substance of the nature of delessite into
biotite would require little more than the elimination of most of the water. Such
changes as these are found to be among the earliest results of the metamorphic
action. Again, part of the new-formed feldspar in the altered volcanics seems to
arise from the regeneration of original feldspar. This is well seen in the porphy-
ritic crystals in the lavas and in those scattered through some of the ashes, the old
turbid feldspar substance being replaced, partially or wholly, by new pellucid
material ; but the pseudomorphs no longer consist of single individuals, and one
cannot positively assert that they are chemically identical with the original feld-
spar. The other new-formed minerals for the most part indicate atomic rearrange-
ments of a more complex order.

The minerals generated in the metamorphism of the volcanic rocks are numerous,
at least in the basic and intermediate groups. Most important in the list are quartz ;
various feldspars ; biotite and allie dmicas ; green hornblende, actinolite and tremo-
lite ; a lime-augite ; sphene, rutile and ihnenite ; magnetite, pyrite and pyrrhotite.

In all the volcanic rocks in their most highly metamorphosed state a large pro-
portion of the bulk is found to consist of feldspars, among which are recognized
orthoclase, albite, anorthite, and some of the intermediate varieties. With this
constant abundance of new-formed feldspars we may correlate the absence or rarity
of certain aluminous silicates, such as garnet, andalusite, staurolite, etc, known as
common metamorphic minerals in many sedimentary rocks. Cyanite and andalusite
occur only occasionally in some of our metamorphosed ashes, and the garnets are
entirely wanting. Such minerals will naturally arise in the metamorphism of rocks
impoverished in alkalies by the ordinary processes of chemical degradation ; and,
in contradistinction to these, the abundant formation of feldspars may be expected
to characterize the alteration of rocks of direct igneous origin. Feldspars, however,
are certainly formed in many metamorphosed sedimentaries, either in addition to
andalusite, etc, or to the exclusion of such minerals whenever the original material
contained sufficient alkalies. The metamorphism of certain flags near the Shap
granite has given rise to abundant feldspars, while garnet and chiastolite are absent
and andalusite is certainly n< >t characteristic. So far as our data go, this seems to be
a more common thing in the older than in the newer sediments. Broadly speaking,
we may expect the newer detrital rocks, in so far as they are derived from older
sedimentaries, to become increasingly poor in alkalies.* The apparent reluctance
of some geologists to admit feldspar as a highly characteristic product of extreme
thermometamorphism may be due to the fact thai the minuteness of the grains in
most cases, the rarity of twinning, and the singular clearness of the mineral make
it often easily mistaken for quartz. It is instructive to compare the ultimate
destruction of the feldspars in extreme dynaniometamorphism.

♦ Taking at random the analyses of " Thonsehiefer " given by Both, rejecting only those cases in
which the stratigraphy is known to beat fault, I find that twenty-one examples grouped under
«' Silur " give average percentages 3.864 of potash and 1.226 of soda; twentj seven under " Devon "
mid " Culm" give 2.701 of potash and 0.973 of soda.

20 PROCEEDINGS OF WASHINGTON MEETING.

A brown mica referred to biotite has been formed abundantly in many of the
rocks studied : sometimes directly from augite, more often from the decomposition
products of that mineral and the feldspars. Besides the flocculent clusters of scales
occupying the place of vanished pyroxene, there are often minute flakes of biotite
scattered through the regenerated feldspars alluded to above. In spots where more
lime was present, as, for instance, within the vesicles of the lavas and in cer.
tain little veins which must have been occupied in part by calcite, green hornblende
occurs instead of biotite ; and some little veins, more calcareous than the others, are
converted instead into a granular monoclinic pyroxene. This pyroxene must, from
chemical considerations, be one rich in alumina as well as lime — an omphacite rather
than a diopside. The distribution of these various minerals in the metamorphosed
volcanics is a good illustration of the way in which the products formed at any
point depend on the chemical composition of the mass in the immediate neighbor-
hood of that point. Prior to metamorphism certain substances were uniformly dis-
tributed through the rock, while others, owing in great measure to weathering
action, were concentrated in particular spots; from this results in part the wide
variety of secondary minerals frequently met with.

The titaniferous minerals afford another instructive example. Titanic acid in
some form seems to have been pretty uniformly distributed through many of these
old volcanic rocks. In the metamorphosed products it is for the most part taken
'up by the mica (typical biotite containing nearly "i per cent, of titanic acid) ; but
where there has been sufficient lime to form hornblende or omphacite in place of
biotite, the titanic acid appears as sphene ; where iron oxides were present in some
abundance we find ilmenite ; and again, in some of the rhyolitic ashes very poor
in lime and iron, simple rutile occurs. Such facts certainly point to the conclusion
that in the processes of thermometamorphism there is very little interchange of
substance except between closely adjacent points.

Of some significance in this connection is the constant preservation of the former
structures of the rocks, despite extreme metamorphism of their material. The
ovoid vesicles of the andesites, filled previous to the granitic intrusion by the ordi-
nary weathering products, are still perfectly distinct even in the most highly meta-
morphosed examples. The flow-structures of the lavas and the lamination of the
ashes, whenever they were distinctly pronounced, have been well preserved, being
often emphasized by a certain foliation due to the parallelism of biotite flakes.
and then indistinguishable from typical micaschists or microgneisses. In places
where the rocks have been cleaved before metamorphosis, this foliation follows the
cleavage. The macrospherulites in the rhyolites have at an early date undergone
changes common in the older acid lavas, giving rise to a segregation of different
materials in alternating concentric shells, and tins structure is beautifully retained
in the metamorphosed examples, the several distinct shells giving rise to different
secondary products, and the concentric partings being defined by special minerals
due to " agents mineralisateurs." A calcareous breccia overlying these acid lavas
contains angular fragments of rhyolite, and these, even close to the granite, retain
their micro-spherulitic and other structures, besides a system of minute perlitic
cracks now occupied by little veins of pyroxene which clearly represent calcareous
infiltrations from the matrix of the breccia. Such striking instances of the preser-
vation of minute structures negative the idea of any considerable interchange of
material between different parts of the rocks affected, and by implication suggest

A. HAKKER THERMOMETAMORPHISM. 21

that the total chemical composition of the rocks has remained substantially the
same during the metamorphic processes.

All these metamorphosed rocks, though dating from pre-Carboniferous and prob-
ably early Devonian times, present a remarkable freshness of aspect in all their
constituent minerals. This is very noticeable in thin slices cut to show the junc-
tion of the granite with the volcanics, the feldspars and biotite of the former rock
having all the usual signs of weathering decomposition, while the same minerals
in the metamorphosed rocks retain unimpaired their pristine clearness. This im-
munity from weathering action appears to be a characteristic feature of metamor-
phic products, whether formed by thermal or by dynamic agencies, but I have not
met with any attempt to frame a general explanation of it.

So far I have treated the metamorphosed volcanics as a whole, without distinc-
tion of the three groups. In the basic and intermediate groups of lavas the changes
produced follow very closely the same lines. The original mineralogical differences
between the two groups lay chiefly in the relative proportions of their several con-
stituents and in the nature of the feldspars, and the metamorphosed representatives
do not show any more essential difference. All the foregoing remarks apply to
both groups alike, and apply to the fragmental as well as to the fluidal members.
In the inner part of the aureola, indeed, the ashes have to be distinguished from
the lavas by structural rather than mineralogical characters.

The acid rocks present a different set of phenomena. In the vicinity of the
granite they often consist of an exceedingly fine grained aggregate of clear feldspars
and quartz. From this we might suppose that the metamorphism has induced
crystallization in rocks originally largely glassy or with special structures not far
removed from the vitreous ; but such an inference would not be warranted. In
other places we find examples which show little or no evidence of any alteration
at all. For instance, I have already mentioned rhyolite fragments in a highly meta-
morphosed breccia, which still retain in perfection their micro-spherulitic structure.
This is a case in which the visible structure is so intimately hound up with the
molecular that one can scarcely imagine a rearrangement of the latter while the
former remains uneffaced, and we are almost driven to the conclusion that the
fragments are practically in their original condition. This slight susceptibility to
thermometamorphism is perhaps to be correlated with the simple chemical compo-
sition of our rhyolites, which contain very little iron or lime and no magnesia; so
that they have little more than the elements of acid feldspars and quartz. The
evident alteration of some of the rocks, on the other hand, may be referable only
in part or not at all to thermal metamorphism connected with the intrusion ; for, as
already noticed, these rocks have often been affected by earlier changes both physi-
cal (devitrification) and chemical (silicification). The ashes associated with the
Lake district rhyolites have behaved, as a rule, in a precisely similar manner; hut
at some horizons, where a certain amount of magnesia and iron oxides was present,
we find to a limited extent the same production of biotite, etc., that characterizes
the metamorphosed andesitic ashes. It is evident that in the fragmental volcanic
rocks, with their heterogeneous constitution, we cannot expect the chemical group-
ing into acid, intermediate, basic, to hold so exactly as in the lavas. It should be
noted, as a further point of interest, that the rhyolitic ashes have been more decom-
posed than the corresponding lavas prior to metamorphism, and the consequent
loss of alkalies has caused andalusite and cyanite to he formed among the metamor-
phic products iu place of the usual feldspars, though only to a limited extent.

22 PROCEEDINGS OF WASHINGTON MEETING.

Summarily, the chief results as regards the thermometamorphism of volcanic
rocks in the English Lake district are as follows :

1. Basic and intermediate lavas and ashes, especially when affected to any extent
by weathering processes, are as readily metamorphosed by heat as are argillaceous
sediments. Acid lavas and ashes of simple chemical composition may, however,
be very little modified, even by a very high temperature.

2. Feldspars of various kinds, formed sometimes by the rejuvenation of old
feldspars, sometimes by recombinations from other minerals, are universally present
in abundance among the new-formed products in the advanced stages of metamor-
phism. Andalusite, garnet, and some other aluminous silicates common in meta-
morphosed sedimentary rocks are, as a rule, absent.

3. The characteristic ferromagnesian minerals generated are biotite and green
hornblende, augite being exceptional ; and the formation of one or other of the
three minerals depends especially upon the percentage of lime in the material
metamorphosed.

4. The only changes in the total composition of the rocks of which we have any
evidence in this district are those occasioned by a loss of water and carbonic acid,
and rarely and to a limited extent by an accession of hydrofluoric and boric acids.

I remarked at the outset that investigations into the effects of thermometa-
morphism may be expected to throw some light on problems connected with the
origin of crystalline schists. The suggestion cannot be properly developed in this
place. It may be pointed out, however, that the post-Silurian intrusions of the
Lake district, including those of Shap fell and Eskdale, can clearly be referred to
the great crust movements which there brought the Silurian period to a close, and
which impressed on the whole district its peculiar geological structure. The effects
of the lateral thrusts which then operated did not there reach anything like the
intensity displayed in the region of the Scottish Highlands, but they furnish, per-
haps on that account, an instructive study. Had the mountain-making processes
progressed in the Lake district to the same stage as in northern Scotland, we should
have dynamic superimposed on thermal metamorphism in the petrographic com-
plex formed by the great intrusions, in their minor off-shoots, and in the adjacent
altered rocks , but the results of the thermometamorphism would still remain as a
factor in the final product*

The paper was discussed by A. C. Lane, Thomas Macfarlane, of Ottawa,
Canada, C. R. Van Hise, and the author.

After announcements from the chair, Mr. J. F. Kemp, of the Commit-
tee on Photographs, announced that the suite of photographs collected
by the committee was on exhibition in the Library of the University.

The Society then took a recess until 2 o'clock p. m.

*Marr : Quart. Journ. Geo!. Soc, vol. xlvii, 1891, p. 328.

Afternoon Session, August 24.

The Society reassembled at 2:20 p. m.
The first paper read was :

THE LOWER SILURIAN (oRDOVICTAN) ICHTHYIC FAUNA AND ITS MODE OF

OCCURRENCE.

BY C. D. WALCOTT.

This paper was dicussed by Dr. Friedrich Schmidt, Professor E. W.
Claypole, Professor E. D. Cope, Dr. Karl von Zittel, Dr. Otto Jaekel, and
the author. It is printed elsewhere in this volume.

The following paper was then read :

THE PLANT-BEARING DEPOSITS OF THE AMERICAN TRIAS.

BY LESTER F. WARD.

Contents.

Introduction page 23

American Distribution 26

Foreign Distribution 28

General Conclusions from foreign Distribution 31

Introduction.

Having been requested by the Director of the United States Geological Survey to
prepare an essay on the correlation of the American plant-bearing deposits of the
United States, so far as indicated by their respective floras, I entered upon this work
in February, 1888, and have continued it as opportunity permitted to the present
time. The formations were taken up in their order of succession, beginning with
the lowest, and the treatment of the Paleozoic horizons was completed, subject to
revision, in July, L889. The Trias was then taken up and brought to a conclusion
near the end of L890. The next higher Mesozoie floras are now in hand.

The plan of treatment lias been to give first a historical account of the discovery
of vegetable remains in each formation, followed by such citations of opinion relative
to its age as will show the progress hitherto made in fixing its geological position,
and then to c pile and discuss the paleontologieal data, and make thorough com-
parisons of each flora and florule with all others that contain the same or similar
vegetable forms.

In the present paper I shall confine myself to the Triassic deposits of the United
States, as having an especial interest from this point of View: first, because their
precise age has been much discussed and lias not Keen definitely settled ; and sec-
ondly, because 1 1 j * - paleontologieal data, meager in all departments, consisl so
hugely of fossil plants.

2-4 PROCEEDINGS OF WASHINGTON MEETING.

The lower members of the Trias corresponding to the Buntersandstein and
Muschelkalk of Europe, if present at all in the United States, are not believed to
have furnished any of the fossil plants that are referred to that system. In fact,
although the Triassic beds of this country have in some places a great thickness,
and although there are indications that those of certain localities occupy a some-
what different position from those of others, still, taking all the evidence into the
account, it seems probable that not only all the plant-bearing strata, but also all the
rocks which are known as Triassic within the limits of the United States, belong
near the top of the system and represent the upper Keuper, or perhaps the upper-
most of them may correspond to the Rhetic of the Old World nomenclature.

As the true Permian is scarcely found within our borders, it will be perceived
that between our rich plant-bearing Carboniferous formation and the next higher
deposits carrying vegetable remains a wide chasm exists, measured by an immense
period of time. It is therefore not to be expected that any traces of the Paleozoic
flora will be found in the comparatively recent deposits of the upper Trias. Such,
indeed, is the case, so far as we now know these floras, and we have to regard these
later deposits as the beginning of a new era in the history of plant life.

It is true that Rogers, Bunbury and others of the earlier authors who described
the fossil plants of the Richmond coal field supposed that they had found speci-
mens of Lepidodendron, Sigillaria and Catamites ; but it is now known that this is not
the case ; that the supposed lepidophytes belong to the coniferre, and that the alleged
Calamiles was a gigantic Equisetum. Specimens of this last were sent to Brongniart,
and it was upon his authority that they were referred to Catamites (C. suckowii) ;
but Brongniart himself expressed doubts in regard to their relation to Calamites,
and it may be worth our while to hear what he says on that point. He made the
American specimen to constitute a variety of that species, and on this he remarks
as follows :

" La var. dont la surface externe est assez mal eonservee, se rapporte cependant a cette espece
par sa forme generate et par la termite de l'eeorce. Les cotes sont seulement plus convexes, ce qui
pent tenir a une moindre compression ; car ces tiges, qui etaient probablement verticales, parais-
sent avoir ete comprimees dans le sens de leur longueur, et presentent des replis nombreux qui
semblent indiquer combien leurs parois etaient minces et flexibles. Cet echantillon est meme fort
remarquable sous ce rapport, et prouve que ces tiges etaient fistuleuses comme celles des Equisetum
vivans."*

This species, which is the Equisetum rogersi of Fontaine, perhaps comes the
nearest to the connecting link between the Carboniferous and the Mesozoic of all
the American forms, but there is no doubt of its generic distinctness from Calamites.
It is possible that when the palissyas and other conifers of the Trias are better
known a close relationship will be found to exist between them and some of the
allied strictly Permian conifers ; but upon this no important conclusions can now be
based. The Triassic flora is also found to be almost as completely cut off from the
floras that are known in the United States above that horizon as they are from
those below it. If any distinctly Jurassic strata exist within our borders they are
not as yet known to carry fossil plants, and the next higher horizon at which these
are found is that of the Potomac formation of Virginia and Maryland, or the per-
haps equivalent Kootanie deposits of the great falls of the Missouri and the Trinity
division of Texas. These, appearing to be nearly of the same age, ought all to
belong to the lower Cretaceous.

•Histoire des Vegetaux fossiles, vol. i, 1828, p. 126.

L. F. WARD — PLANTS OF THE AMERICAN TRIAS. 25

The flora of the Kootanie and the Trinity is very little known, but the Potomac
formation has furnished an abundance of vegetable remains; yet, no single species
of the Trias is found to occur in that formation. There are, however, six species in
the Potomac flora which resemble those of the Trias sufficiently to admit of com-
parison. ( )f these, three are ferns, two are cycads, and the remaining one is a Sagen-
opteris. As the local habitat of these species was nearly the same at the two
epochs, there is considerable probability that the Potomac plants may have been
the direct descendants of those of the Trias.

Still, to all intents and purposes, the Triassic flora of the United States may be
regarded as a distinct and independent flora. So considering it, there are two
points of view from winch it can be treated when studying more especially the
question of its age : We may inquire first whether it constitutes one homogeneous
flora, or whether the different parts bear evidence of having been deposited at con-
siderably different periods of time. In the second place, we may inquire what its
relations are to other known floras of the globe — in other words, when treating of
the species of fossil plants found in this group, we naturally concern ourselves, first,
with their American distribution, and secondly, with their foreign distribution.

American Distribution.

I have divided the American plant-bearing Trias into five distinct geographical
areas, corresponding nearly with so many geological basins :

First, that of the Connecticut valley, so long known to geologists from the dis-
covery in it of the tracks of animals. In this I assume the Southbury area, though
isolated geographically, to be included.

Second, the New Jersey and Pennsylvania area, extending from the Hudson
river to the Potomac. I have not used the term "palisade area," which was em-
ployed by Professor Dana, because he makes this to include also the Triassic de-
posits of Virginia, and even to embrace the Richmond coal field. It would be
logical, it is true, to make this embrace the Piedmont deposits, extending as far
south as Charlottesville, in Virginia. Between this and the Virginia coal field
there is a complete interruption as greal as that between the Connecticut valley
and the palisades. As all these areas may have once been confluent, it is not con-
sidered important to maintain their strict geological relationships.

Third, the Virginia area which I make to include all the deposits in that state,
those of the Richmond coal field having furnished nearly all the fossil plants.

Fourth, the North Carolina basins or areas, including the North Carolina coal
field. The deposits in this state are not continuous, but consist of several isolated
basins.

Fifth, the Western area. This includes all the deposits in Arizona and New
Mexico, and also in Colorado and other adjoining states and territories where
known, and constitutes the Shmanimp formation of Powell. Fossil plants other
than silicilied wood have been found only in New .Mexico in the vicinity of Abi-
quiu and the copper mines. Silicilied wood is found strewn ahout upon the plains
in vast profusion wherever t he formation exists.

Keeping in view these live basins, it is necessary lirst to eliminate all the forms
which are confined to any one basin. We lind that out of a total of i pi species be-
longing to the American Trias, ;!:"> occur in the Connecticut valley, L8 in New
Jersey and Pennsylvania, 56 in Virginia (including the single species found in

l \ Bull. Gi ol. Boo. Vm., Vm . :'., Ism

PROCEEDINGS OF WASHINGTON MEETING.

Maryland), 52 in North Carolina, and 13 in New Mexico and Arizona. Of course,
many of these species occur in more than one of these areas, the extent of the over-
lapping amounting to 43 species, or a little over one-third. "We thus learn that 85
of the 119 species, or considerably over two-thirds, are confined to one basin — in
fact, to one state or territory. So far, therefore, as the question of distribution or
parallelism within the United States is concerned, these 85 species are of no value,
and our present discussion must be confined to the remaining 34 species which are
found in two or more of these localities.

Considering these 34 species, we find that there are common to the Connecticut
valley and to the New Jersey and Pennsylvania area, 5 species ; to the Connecticut
valley and the Virginia basin, 5 species ; to the Connecticut valley and North Caro-
lina basin, 6 species ; to the Connecticut valley and great Western basin, 1 species ;
to the New Jersey and Pennsylvania area and the Virginia basin, 7 species ; to the
New Jersey and Pennsylvania area and the North Carolina basin, 10 species ; to the
New Jersey and Pennsylvania area and the great Western basin, 2 species ; to the
Virginia and North Carolina basins, 20 species ; to the Virginia and Great "Western
basins, 2 species ; to the North Carolina and great "Western basins, 2 species.

These facts may be expressed in tabular form as follows :

Areas.

New Jersey and
Pennsylvania.

•-
O

New Mexico and
Arizona.

Connecticut valley

(i
10

New Jersey and Pennsylvania

Virginia

If, in order to avoid the repetition of the names, we number the basins from
north to south, that of the Connecticut valley being 1 ; New Jersey and Pennsyl-
vania, 2 ; the Richmond coal-field, 3 ; the North Carolina basin, 4 ; and that of the
far west, 5 : then we observe that there occur in the first, second and third basins 1
species; in the first, third and fourth basins, 1 species; in the second, third and
fourth basins, 3 species ; in the first, second, third and fourth basins, 1 species ; in
the second, third, fourth and fifth basins, 1 species, and in all of the five basins, 1
species. This last is the widely diffused Clieirolepis munsU ri.

There has been no serious question as to the parallelism of the New- Jersey and
Connecticut valley deposits, and as only eight unsatisfactorily determined species
occur in Pennsylvania it is impossible to argue from so meager data. Again, the

L. F. WARD — PLANTS OF THE AMERICAN TRIAS.

fact that twenty species are common to the Richmond coal field and that of North
Carolina argues very strongly for the near parallelism of these deposits. The princi-
pal problem, then, is whether the Connecticut valley basin and the New Jersey area
are really of the same or nearly the same age as the coal-beds of Virginia and North
Carolina. The five species common to the Connecticut valley and Virginia, and
the six species common to the Connecticut valley and North Carolina weigh for all
they are worth directly upon this problem. With regard to the New Mexican beds,
we find that out of the thirteen species there found, only two occur also in the east.
These are the wide-spread forms Cheirolepis munsteri and Palissya braunii, which
have been found in both the northern and southern basins.

Notwithstanding the thoroughness of this analysis, it nevei'theless leaves the
mind in a somewhat unsettled condition with regard to the main question as to
whether the data sustain the view that these different deposits are really shown by
the fossil plants to occupy about the same horizon or to have been laid down at
about the same epoch. This is chiefly due to the great difference in the extent to
which the different basins are represented by the fossil plants, especially to the
relative meagerness of the flora of the Connecticut valley and New Jersey as well
as that of the west as compared with the abundant flora of the Virginia and
North Carolina basins. The problem is, therefore, to eliminate this element of
obscurity and to reduce all the basins to some common basis of comparison. This
can only be done by the use of percentages. For example, it will be instructive
and will be the best that we can do to show what per centage of each florule— that
is, of the plants of each distinct basin — is also found in any of the other basins.
For this purpose we may take the gross number of species or forms that occur in
each basin regardless of overlapping. From this gross number we may deduct all
those that are confined to each basin, the remainder being common to it and some
other basin. Then calculating the percentage of these common forms to the total
number occurring in each 1 >asin, we shall not "only have a clear idea of the relation of
each florule to the American Trias taken together, but also of the relative homo-
geneity of all the florules.

The following table will show this :

Basins or areas.

( (ccurring
in —

Ciiufined
to—

( Jommonto,

and some
other ba-
sin.

Per cent
in other
basins.

Connecticut vallev ....

18 9

New Jersey and Pennsylvania. . .
Virginia and Maryland

84
25

27
2

72
39

North Carolina

.'.i'

New Mexico and Arizona

i:»

From this table it appears thai none of the basins excepl thai of the weal con-
tains Less than 39 per cenl of common species, and thai one of the basins, viz, that

28 PROCEEDINGS OF WASHINGTON MEETING.

of New Jersey and Pennsylvania, has 72 per cent of its plants common to other
basins, while that of North Carolina has 52 per cent common. These two remark-
ably exceptional cases are the smallest of the five basins. Of the three principal
basins, that of the Connecticut valley has 39 per cent ; that of Virginia, 39 per
cent ; and that of North Carolina, 52 per cent of common species.

Considering that we are dealing with a fossil flora, a large number of whose
forms are not specifically determinable and most of the material of which is frag-
mentary, the fact that in all but one of these five florules of the American Trias
the number of forms sufficiently distinct to be clearly determinable specifically
and to be identified with forms in other basins, ranges from 39 to 72 per cent may
be taken as very strong evidence of the general parallelism of these four basins.

As regards the western deposits, notwithstanding the poverty of their present
known flora, there seems to be some indication that they were not laid down at
the same exact epoch as those of the Atlantic coast; but, assuming such an asyn-
chronism, the question as to whether they are earlier or later cannot be profitably
considered with the present insufficient data.

Foreign Distribution.

The foreign distribution of the Triassic flora has been a much more difficult
problem, and has required a large amount of careful analysis. Five tables have
been prepared with the object of exhibiting it to the fullest possible extent.* In
discussing this problem all species which are entirely without foreign distribution
or affinity are of course omitted. The remainder are divided into two classes:
First, those which are actually found in other formations and localities than the
American Trias; and second, those which, though not so found, are obviously re-
lated to other species that are. There are 40 species belonging to the first, and
17 to the second of these two classes, making 57 species which have diagnostic
value in determining the age of the formation.

In the first or most extended of the tables of foreign distribution, these 57 species
are introduced and the foreign distribution, both geological and geographical, is
shown. The amount of detail, however, is so great that it is impossible to discuss
the problem without further analysis. The first step in such analysis has been the
preparation of a table from the geological point of view, giving under each forma-
tion the species which are common to it and the American Tiias. In some respects
this table goes still further into details than the former one, and a full explanation
of many of the cases presented in it is made.

The third of the tables of foreign distribution relates exclusively to the first class
above named — that is, to the American Triassic species which have a foreign dis-
tribution,— and gives each species with such distribution, only, however, as regards
the ge< (logical position, leaving the geographical range to lie determined by reference
to the table last considered.

finally we have a recapitulation of all the data thus far set forth showing the
number of species occurring at each of the other horizons in the total distribution :

♦Several large charts illustrating so far as possible the- data contained in these tallies were ex-
hibited before the Society. These cannot conveniently be introduced here, but will appear in the
final essay.

L. P. WARD — PLANTS OP THE AMERICAN TRIAS.

Summary of the geologic and systematic Distribution of American Triassic Plants and

their A /Hex.

Ferns.

Equiseta.

Rhizocarps.

Cycads.

Conifers.

Total.

Geological forma-
tions.

H
ID

1— 1

d
o>

1— 1

■+J

Potomac .

4
1
5

2
4

Wealden

Oolite

2
3

1
3

o
O

1
1
2
1
1

1
1

•>
•J

O
O

7
8
1

14
8

20
2
3

Lias

^?,

Lower Jurassic . .

Rhetic

8
5
5

o
O

5
5
3

6
3
5

Triassic

Keuper

Muschelkalk .

Buntersandstein

In this table the classification of the several types of vegetable life has been intro-
duced. It will be seen that there are represented among the plants that have a
foreign distribution ferns, Equiseta, rhizocarps, cycads and conifers. Considering
the geological range, we observe that it extends from the Buntersandstein to the
Potomac formation or lower Cretaceous ; but if we scan the columns closely we per-
ceive that none of our species actually occur above the Oolite, the only forms here
compared in the Wealden and Potomac being forms allied to American Triassic
species. On the other hand, it is remarkable that the largest number of identical
forms occurs in the Keuper. This results from the very large number that Dr. Stur
has identified with the plants of the Keuper of Lunz, Austria, and those of Raibl,
in Carinthia, and of certain localities in Switzerland, referred to about the same age.

I have summed up the general results of my investigation of the American Tri-
assic flora both from the geological and botanical standpoints in the final table
(page 30), to which I now call attention.

We perceive by inspection of this table that the Mora consists of 119 specific
forms, which may for convenience be called species, though many of them are not
specifically determinable and in a few cases they consist of varieties. These 119
species belong to 51 genera, although of the 51 a few are not distinctly named as
genera and some may be merely the fruit of the same genera that are also found in
other forms.

Looking to the botanical affinities of these forms, we find that the most of them
can be classified under some of the general grand divisions of the vegetable king-
dom, although in a few cases this determination is very uncertain. We thus have
what seem to he representatives of eight great types of vegetation. These types,
beginning with the lowest and naming them in the supposed ascending order of
their Structure, are, first, fucoids, that is some kind of seaweed ; second, terns ; third,
equiseta; fourth, lycopods ; fifth, rhizocarps ; sixth, cycads ; seventh, conifers ; and,
eighth, monocotyledons. There remain five genera and six species w hose botanical
affinities are whollv unknown.

PROCEEDINGS OF WASHINGTON MEETING.

Tn<AL

i— | ~ r-. © t-~

lo i—i i^ -r i— i

uAvou>jun jo s;m;[(|

to CO ©

•suopaiAjooouojt

CI Cl (N

C~l

•siajiuoQ

CC OS -f LO

•SpBO^Q

i—i ec ci ^h

•sdaBOOziqjj

co
3

* cO

s
e

■spodt»o^r[

•ujasmbg;

Cl H N -f

•SU.I0J

it ic y; i-

HMHi-

•spioon^j

io ~ ~

02
CO

•l-H

c3
Si

• r-<

03 Q
- DQ PI

* .5.2
a>2§

cd -

02 - - I

I c

R
• —

" o 2 o

«! o

CD=*H
r£ O

02
CD

<i O

^ CD
(1> 02

«S >
™ 2

CD ?

£h"0

re ^

CD
bjD

o
o

cd S

c o

CC °

g>8£

" c3^!

~ .;Z .£
„-, 5PG

& c o

0.2-T5 S

■3 £ ^

O ftc

Oi , ^,

ii co G
i — - j-.

2 E 3

1^3 CD

4-J -iH ^

? rn r|

2 WS - 2
C CD
cp p.,

t<-l - - - ^
O— - - -

as s - s

izi

L. F. WARD — PLANTS OF THE AMERICAN TRIAS. 31

Keeping this botanical classification in view, we may next look at this flora from
the point of view of its geological importance, that is, of ascertaining how many of
these forms have any diagnostic value for geology. To determine this we need to
know the number of forms that are not confined to the American Trias but are
found in other formations and at other localities — forms that have a geological and
geographical distribution. The table shows that only 40 of these forms have such
a distribution, viz, 17 ferns, 4 equiseta, 1 rhizocarp, 13 cycads, and 5 conifers. But
there is another class which has also a diagnostic value, viz, those species which,
having no distribution of their own, are clearly shown to be allied or related closely
to other plants occurring in other formations and localities. Of these there are 17,
viz, 7 ferns, 2 equiseta, 7 cycads, and 1 conifer. Putting these two elements together,
we have 57 diagnostic species, viz, 24 ferns, 6 equiseta, 1 rhizocarp, 20 cycads, and (i
conifers. This leaves 62 species, or over 52 per cent, not found in any other forma-
tion and not allied to any species known elsewhere ; therefore without diagnostic
value.

GENERAL CONCLUSIONS FROM FOREIGN DISTRIBUTION.

It will be seen that tables three to six, inclusive, relate to the foreign dis-
tribution of the fifty-seven diagnostic species, and it may now be inquired in general
terms what is the final outcome of these extended comparisons. Do they serve in
any sense to correlate the American Trias with any of the Old World deposits ? If
the answer is that they do not enable us to say with positive certainty that the
American deposits are exactly parallel with any others, this is a very different thing
from saying that the facts thus presented are worthless, or that they do not greatly
increase our knowledge of the position which they occupy in the geological scale.

It must be remembered that it is chiefly from the plants that we derive this
knowledge. All discussions of the animal remains, even the abundant ichnites of
the Connecticut valley, left their age enshrouded in doubt. Plarly mistakes in de-
termining the vegetable remains caused opinion to fluctuate all the way from the
Oolite to the Carboniferous. The present accurate knowledge fixes the horizon
with almost absolute certainty at the summit of the Triassic system, and narrows
the discussion down chiefly to the mere verbal question whether it shall be called
Rhetic or Keuper. At present, as we saw in the detailed consideration of the facts
brought out by the fourth table, the beds that seem to be most nearly identical, so
far as the plants are concerned, are those of Lunz, in Austria, and of Xeue Welt,
near Basle, in Switzerland. These have been placed by the best European geolo-
gists in the upper Keuper. Our American Trias can scarcely be lower than this, am 1
it probably cannot be higher than the Rhetic beds of Bavaria.

In the discussion following the reading of the paper, Mr. G. K. Gilbert
remarked that the four eastern provinces are more closely related by
their floras than any one of them is related to the one western province,
and that the same conclusions were reached by a consideration of the
purely physical features of these provinces.

The author of the paper said that the species of the American Trias

have more affinities with the meager flora of the European Keuper than
with the much more abundant flora of the Rhetic.

32 PROCEEDINGS OF WASHINGTON MEETING.

The next paper was entitled :

STUDIES IN PROBLEMATIC ORGANISMS — THE GENUS SCOLITHVS.

BY JOSEPH F. JAMES, M. S., F. G. S. A., ETC.

In 1840 Professor S. S. Haldemann described a fossil occurring in a sandstone of
southeastern Pennsylvania as follows:*

" Fucoides (?) linearis : Stem simple (never branched), rectilinear, surface nearly even; diameter
% to % inch, length several feet, cylindrical or compressed. Locality, south of Reading and north
of Columbia, Pennsylvania, being the oldest fossil in the state, occurring in the tirst stratified rock
above the gneiss. 06s.: I discovered this fossil in 1835, and described it about three years ago as
Skoliihos linearis, and because the genus Fucoides is composed of heterogeneous materials. The
characters of t\te sub-genus Skolithos are: Stem free, cylindric or sub-cylindric, vermiform or
linear, never branched; structure unknown."

This is the first introduction of the name Scolithus into geological literature,
although forms now recognized as belonging to the genus had been previously
mentioned. In 1833 Professor Edward Hitchcock noticed a fossil supposed by him
to be a fucoid occurring in the New Red sandstone (Triassic) of Deerfield and Green-
field, Massachusetts. He described it f as varying from j'^ to 1 inch in diameter,
running through the rock either in the direction of the lamina?, when it is more or
less compressed ; or at right angles or obliquely to the laminae, when it is cylindri-
cal. It is frequently curved but never branched. A specimen broken transversely

showed the cylinder to be made up
of convex layers of sandstone, piled
one upon the other (figure 1). On
one side of the rock were button-
like protuberances and on the other
side corresponding cavities. It was
supposed to resemble Fucoides brong-
niarti, Harlan, but no name was
applied to it. In the second edition
of the Geology, however, published
in 1835, the same fossil is described
(pp. 235, 23(3) ; and, after stating the
conclusion that it differed from Fu-

Figube 1 — Scolithus shepardi, Hitchcock (sp.)
Hitchcock.)

(After

coides bronguiurti, Hitchcock proposed to call it F. shepardi. The cylindrical form
passing through the laminae of the rock seems to be congeneric with Scolithus,
although the compressed form, parallel with the lamina?, may not be the same.
The genus Fucoides having been broken up and abandoned, I propose that this form
be called Scolithus shepardi. In the final report on the geology of Massachusetts,
published in 1841, the fossil is again described in the same language as that pre-
viously used.J Two figures are also given, one of which is reproduced in figure 1
of this paper.

In 1838 Professor W. B. Rogers in describing the rocks of Formation I, as it
occurred in Virginia, referred to markings at right angles to the stratification which

♦Supplement to No. 1 of "A Monograph of the Limnaides or Fresh-water shells of North America."
October, 1840, p. 3.
f Report on the Geology, Mineralogy, etc, of Massachusetts : Amherst, 1833, p. 233.
X Volume ii, pp. 4">.">. 456; fig. 95.

J. F. JAMES — THE GENUS SCOLITHUS.

were said to penetrate " in straight lines to great depths in the rocks, and from
their frequency and parallelism determining its cleavage in nearly vertical planes.
These markings are of a flattened cylindrical form, from \ to TV of an inch hroad,
giving the surface of the fractured rock a ribbed appearance, and resembling
perforations in sand which have been subsequently filled up without destroying
the distinctness of the original impression." .Similar markings arc stated to be
found higher up in the series.* The form here described is now recognized as
Scolithus linearis, Ilaldemann.

In 1842 Lardner Vanuxem referred to certain fucoids found in the Oneida con-
glomerate, near New Hartford Center, New York. He described them as smooth,
cylindrical and ramose, many about | of an inch in diameter, and arranged verti-
cally in the rock.f It is possible that this form is the same as that subsequently
described and illustrated by Professor Hall. Vanuxem did not, however, give the
fossil any name.

In 1843 Professor James Hall % illustrated Fucoides verticalis, stating that it consisted
of small, round stems extending vertically through the strata, as if they had been
growing at the time
the sand was depos-
ited around them.
They are said to al-
ways characterize the
upper part of the Por-
tage group (see figure
2) . Whether the same
or not, a species under
the name of Scolithus
verticalis was described
by Hall in 1852 as oc-
curring in the Medina
sandstone. >; If the two
forms are to be consid-
ered as distinct, that
from the .Medina must
receive a new name.||

In L847 appeared the firsl illustration ami the second description of Scolithus
linearis. It was by Professor Hall, in volume 1 of the Paleontology of New York,
page 3. It was referred to by him as possibly a plant, though no opinion is ex-
pressed as to its affinities. He said it was " apparently confined to the Potsdam
sandstone," and it occurs in the valley of hake ( 'ham plain, near Adams, Massachu-
setts, in sandstone of the same age in New Jersey and Pennsylvania, "and it may
he traced in the same rock through Maryland and Virginia to Tennessee." Figures

are given of specimens from Adams Massachusetts, and from Pennsylvania. Those

• Geology of the Virginias. Report of Progress of the Geol. Sur. of Virginia for 1837. Reprint
edition, 1884, p. 168.
f Geology of New York, Third Geol. District, 1842, p. 76.

i leology of New Fork, Report ol F th Geol. District, 1843, p. 242.

I Paleontology of \. v.. \..i. ii. 1862, p. 6.
For this I would proposi the name S. elintont nsis, as there cannol be two species of similar name
in the same genus.

V- Bi n. Gboi 3oi \-.i . \ ol. 3, 1891.

Ficnu: 2 — Scolithus verticalis, Hall (sp.). {After Hall.)

34 PROCEEDINGS OF WASHINGTON MEETING.

we give below (figures 3 and 4), taken from Walcott's paper on the Olenellus fauna *
do not differ in any essential character from the figures given by Hall.

In 1851 Professor H. Goeppert published a paper on the flora of the Transition
rocks,t in which he refers to Scolithus linearis as a plant under the name of Scoleco-
lithus linearis.X

In the following year (1852) Professor James Hall described as a new species
Scolithus n rticalis, from the Medina sandstone.*! As noted above, he had mentioned
Fucoidcs verticalis from the Portage, and a comparison of the two forms fails to show

' -„

■

Figure 3 — Scolithus linearis, Haldemann. (After Figubb 4— Scolithus linearis, Haldemann. {After

Walcott.) Waleott)

rrii>- cast of ;i Bingle tube preserved in a coarse Tubes filled with sand of a darker color than

sandstone. the matrix.

any difference between them. He referred the form, without any question, to the

vegetable kingdom. His description, which is meager, is as follows :

" Plant composed of smooth round stems, which penetrate the strata vertically. This species is
smaller than the one in the Potsdam sandstone, though resembling it in its general characters."

Our figure 5 is copied from that given by Professor Hall. There is scarcely any
feature except its geological position to distinguish it from S. linearis.

In the same year (1852) we have the first reference of Scolithus linearis to the
animal instead of the vegetable kingdom. Logan, in a paper on foot-prints occur-

*10th Ann. Rept. U. S. Geol. Survey. 1890, pi. 63.
fZeit-'-ln'. der Deutsche geol. Oesell., Bd. 3, 1851.

J This paper is noticed by T. K. J[ones] in the Quart. Jour. Tieo!. Soc. London, vol. viii, part 2,
] - >2, pp. 18-23.
£ Paleontology of X. V., vol. ii. 1852, p. 0, pi. 2 [misprinted iii in text], fig. 3.

J. F. JAMES — THE GENUS SCOLITHUS.

Figure 5 — Scolithus clintonensis (n. sp.)=
Fucoides verticalis, Hall. (After Hall.)

ring in the Potsdam sandstone of Canada,* referred to the species as marking the
sandstone abundantly over considerable spaces, saying that it consists, "where the
rock is weathered, of straight vertical cylindrical holes, of about an eighth of an
inch in diameter, descending several inches,
and where the rock is unweathered of corres-
ponding solid cylinders, composed, apparently,
of grains of sand cemented by a slightly calca-
reous matrix, more or less tinged with peroxide
of iron. Mr. Hall and other American geolo-
gists include them among the fucoids of the
rock, but they appear to me more like worm-
holes. In one or two instances I have perceived
that the tubes are interrupted in their upward
course by a thin layer of sand, a portion of
which descends into them and stops them up;
and from this it would appear that the cylin-
ders were hollow when the superincumbent
sand was spread over them. Whatever may
be the origin of the tubes, they strongly mark
many beds in the upper portion of the sand-
stone throughout the Canadian portions of its
distribution." This opinion has been accepted
by most authors who have written upon the
genus, although some still adhere to the idea
that the fossils are of vegetable origin.

In 1857 Mr. J. W. Salter noted f finding in the Stiper stones of Shropshire, Eng-
land, vertical tubes similar to Scolithus linearis. He proposed to use the term
Scolithus or Scolites for single tubes or burrows, either vertical or horizontal, but the
suggestion does not seem to have been accepted.

In 1858 was published the Geology of Pennsylvania, by Henry D. Rogers. In
the course of this report J Scolithus linearis is alluded to in one place as a plant, and
in another as an annelid burrow. In discussing facts relative to the deposition of
the primal white sandstone he says it must have been deposited in quiet waters,
because of the "universally perpendicular position of its long slender delicate stem-
like fossil, the Scolithus linearis, winch seems to have been enclosed by the settling
sand with as little horizontal bending motion of the stalks from any current as
when a Held of standing corn is enclosed and bedded up in gently-falling snow."

Again, when referring to the fossils of the Primal strata, he says the species was
alluded to in the reports of the Pennsylvania and Virginia surveys under the name
of Tninilii, s.|| He describes it as usually smooth, but sometimes waved or grooved
transversely to the axis ; always perpendicular, " suggesting the idea of perforations
by some marine worm. < hie end of the fossil always terminates at the upper sur-
face of the bed of sandstone enclosing it, and usually in a rudely flattened knob or
bead, giving to the whole a likeness to a large, long pin. This knob is probably a
casl formed in a wide conical funnel-shaped month of a cylindrical perforation."
This form is abundant in the Blue ridge of Virginia and at Chickiea on the Susque-
hanna in Pennsylvania. Similar forms occur in higher formations. The figure

♦ Quart. Jour. Gteol. 8oc. London, rol. viii, 1852, pp. 199-213.
; Quart, .lour. Geol. 8oc. London, rol. xiii, 1857, p. 204.
i Volume -', pp. 780, 816 • 16
I have i n unable t" find any use of this nam ■ in the reports mentioned.

PROCEEDINGS OF WASHINGTON MEETING.

given by Rogers (figure 6) differs somewhat in the annulated appearance from
those ordinarily given, hut it can scarcely lie anything else than Scolithus linearis.
It hears a striking resemblance to Planolites annularius, Walcott, as figured in a

paper on the Olenellus fauna* That figure is
here reproduced (figure 7). The species occurs
in rocks of lower Cambrian age in Washington
county, New York.

In L859 Murchison noted the occurrence of an-
nelid borings in the Stiper stones of England, f
referring them to Scolithus linearis of the Potsdam
M \ ^%JS sandstone of North America. The Stiper stones

\\ ^ # ,t"*i« iMaPm are now considered to be of Lower Silurian age.

. -™ ty ---■?• "'

Figure 7 — Planolites annularius, Walcott.

(After Walcott.)

Figure 6 — Scolithus linearis, Halde
mann. (After Lesley.^)

In 1861 Dr. J. S. Newberry in describing a sec-
tion at Diamond creek, Arizona, % referred to the
presence, in shales lying above and below a sand-
stone, of "great numbers of cylindrical bodies
which resemble the casts of worm-holes." These
are doubtless Scolithus burrows. The rocks over-
lying the beds with the worm-like bodies are
referred to the Potsdam upon lithological char-
acters and "their great relative antiquity." This
series is now known as the Tonto group, and is
placed in the upper Cambrian.
In 1861 Professor C. H. Hitchcock, in describing the Georgia group of Vermont, ||
referred to Scolithus as follows: "The Scolithus linearis (Hall) is regarded by some
as a plant, by others as a relic of an articulate animal. It generally presents the
appearance of numerous linear stems, sometimes three feet long. The stems are
generally numerous, and much resemble a series of small pins driven into the rock.
Some authors have stated that the axis of this fossil is invariably at right angles
with the position of the strata. If so, it may be of great service where it occurs in
settling the position of the strata. It certainly would be in both of its localities in
Vermont." "Many have considered this fossil as characteristic of the Potsdam
sandstone. If this be so, then the age of the quartz rock is certainly known. It
certainly has never been described from any other rock ; hut we do not feel autlior-

* Tenth Aim. Rept. U: S. Geol. Sur., pi. 60, fig. :..
f Quart. Jour. Geol. Soc. London, vol. 15, 1859, \>. .'U.S.
% Rept. mi Colorado River of the West, explored under Iv<
I Dictionary of Fossils of Pa., vol. :;, 1890, p. 944.
Geology of Vermont, vol. l, 1861, pp. 356, :;.">7.

in l857-'58, pari Ill, 1861, p. 5G.

J. F. JAMES — THE GENUS SCOLITHUS.

ized to accept the positiveness of its evidence, because (1) of its anomalous char-
acter; (2) because it is found in a metamorphic rock, and may, therefore, have been
altered from some other species of organism, considerably different from the orig-
inal of the Scolithus. For instance, upon the supposition that the quartz rock is
middle Silurian, we should imagine the Fucoides rcrticalis of the < >neida conglom-
erate would change into a form not distinguishable from the Scolithus linearis."
This "quartz rock" is now regarded by Walcott as of lower Cambrian age. The
figure given by Hitchcock is not distinguishable from Scolithus verticalis, Hall (&
clintonensis of this paper).

In the same year Mr. E. Billings* referred to S. linearis as occurring in the sand-
stone at l'Anse au Loup, strait of Belle Isle, differing from the common form of the
Potsdam of Canada, but being identical with that of the upper Primal of Pennsyl-
vania, and with that of the Potsdam of Tennessee (Number III of Safford). Bil-
lings then regarded the form as a plant. The rock at l'Anse au Loup is now
considered to be of lower Cambrian age.

In the same volume f appears a description of a new species, under the name of
Scolithus canadensis. It consists of cylindrical or irregularly prismatic stems (or
rather the cavities in the rock once occupied by such stems) " from 1 to 2 lines in
diameter and from 1 to 6 inches in length, and either straight or more or less
curved. In some specimens several of the stems are in contact with each other,
and when this is the case and the stems have an angular shape they very much
resemble the coral Tetradium. The larger stems are more often straight than the
smaller. The true Scolithus linearis is generally larger and the stems straight and
parallel with each other. It occurs in the upper Potsdam of Canada and on the
eastern side of Snake mountain, Vermont."

The species (figure 8) was illustrated in 1863 by Logan.J who described the holes
as being from fa to £ of an inch in diameter. They sometimes penetrate the rock
vertically several inches, but in gen-
eral they are more or less curved
and distorted. He says :

"The casts of the interior of these cavities
in freshly hroken or unweathered masses
of the rock usually appear as solid cylindri-
cal or angular rods, composed apparently
of grains of sand cemented by a slightly
calcareous matter more or less tinged with
peroxide of in in. The origin of these holes
is not quite certain ; some suppose them to
he the remains of fucoids, others of corals,
while many are of the opinion that they
wire the habitations of small burrowing
marine or shore-frequenting animals."

He also says that the original

specimens upon which the species

was founded differ from those above

described "in being straight and

inure decidedly cylindrical, and are therefore probably a distinct species." Tins

remark is at variance witli the original description of Mr. Billings, as quoted above.

l'*n. i re 8- Scolithus canadensis. {After Lesley. I

* Paleozoic Fossils, l861-'66, p. _'.

fl'. 96; tirst published in 1862.

[Geology of Canada, from the commencement [of the Burvej | (" 1863.

\Op. cit., \i. 943.

Im.::. p. 101.

PROCEEDINGS OF WASHINGTON MEETING.

In 1869 Billings read a paper before the Montreal Natural History Society on
Scolithus and allied fossils. This does not appear to have ever been published, but
from a notice of it given in Nature* we learn the author stated that sometimes the
specimens can be separated from the rock ; that all varieties are marked by undu-
lations; and finally, that specimens from the Potsdam of Canada found by the
geological survey "proved that they were not the casts of worm burrows, but
sponges." Siliceous spicules, generally elongate-pyriform, are found associated.
This is the only reference found in which the sponge nature of ScoIitJius is ad-
vanced.

In 1877 Professor J. D. Dana, in giving an account of the researches of Reverend
Augustus Wing into the geology of Vermont, mentions a species of ScdMius under
the name of S. minutus.f It is not accompanied by any description, and I cannot
find that it has ever been described. The name was probably applied by WTing to
some small worm burrows found during his researches. Professor Ezra Brainerd
has kindly sent me a specimen of this form, and it may be described as follows :

Scolithus mintjtus, Wring. Cavities penetrating the rock in various directions,
generally vertically and opening at right angles or obliquely to the surface. Holes
varying from ■£% to i of an inch in diameter; never branching, but sometimes
slightly curved (figures 9 and 10).

It occurs in the Calciferous formation of Vermont, and its geological position is

perhaps the only reason for considering
it distinct from S. canadensis.
In 1878 Messieurs Miller and Dyer de-

Figure 9 — Scolithus mintitus. Wing. (Original.)
Surface, showing openings of burrows.

Figure 10. — Scolithus minutus. Wing. (Original)
Showing burrows in rock.

scribed a species of Scolith us under the
name of S. tuberosus.t It is quite differ-
ent from any other species of Scolithus
described. The authors say of it :

" The holes (sometimes called stems) are curved or winding, and pass through the rock in an
irregular course, sometime uniting or branching, but never passing vertically through the strata
as in S. linearis, from the Potsdam group. Upon the upper surface of the rock the tubes are pro-
longed into a crateriform elevation, which is rarely at right angles to the surface of the rock.
These resemble, on a smaller plan, the mud elevations, thrown up around the holes, made by the
common crawfish on our fresh-water streams.

"The holes are not. tapering, but maintain a somewhat uniform diameter. Diameter gencrally
about -1 lines; sometimes nearly 3.

" This species resembles the burrow of some animal more clearly than any hitherto described,
and bears no resemblance to any of our fueoids. It has been frequently, but very erroneously,
referred to S. linearis."

* Volume 1, 1800, pp. 248, 249.

f Am. .lour. Sci., :!il sit., vol. xiii. Is77. p. :',42.

J Privately printed pamphlet, entitled < lontributions to Paleontology, No. 2. 1878, p. 5.

J. F. JAMES THE GENUS SCOLITHUS.

Figure 11 — Scolithus (?) tubero*
sms, Miller and Dyer. (After Miller
and Dyer.)

Figure 11 is reproduced from the figure given by the authors. The description
does not agree with the generic description of Scolithus, and it is evidently not con-
generic with S. linearis. It should be referred to a
separate, probably a new, genus.

In 1878 Dr. T. S. Hunt, in a special report on the
trap dikes and Azoic rocks of Pennsylvania,* gave a
short history of Scolithus. He referred to the descrip-
tions of Haldemann, Hall and Eogers, and quoted the
description of Billings and his remarks relative to S.
canadensis. lie said that examples of Scolithus from
the Potsdam of Wisconsin appear to be identical with
S. canadensis, and, although probably distinct, are
more like S. verHcalis from the Medina than S. linearis
from the Primal of Pennsylvania. He says further :
"It would appear that even in the typical Potsdam
sandstone there have been confounded under this
name the marks of distinct and unlike objects." f
Some beds at Port Henry, New York, contain im-
pressions which have been designated Scolithus. These
are described as cylindrical cavities with a central tube. In weathered specimens,
where this central tube has disappeared, the cavities resemble the burrows of a
worm. " But," he says, "in either condition they are evidently very distinct, both
from the prismatic shapes noticed by Billings under the name of Scolithus canadensis
and the transversely grooved cylindrical rods of the Primal white sandstone." J

In 1880 Professor R. P. Whitfield described a form from the P< itsdam of Wisconsin
which he called Scolithus (?) woodi. t
It consists of vertical and usually cylin-
drical perforations, about a line or a
little more in diameter, and from 1 to
several inches in length. They arc
straight or variously bent, lint never
bifurcating or branching. The walls
are usually smooth, but occasionally
one is corrugated (figure 12). In his
comparisons with other forms it was
said that while X linearis is from ,1 to
■' inch thick, and often several feet in
length, the western forms are seldom
even jl, and often /„ of an inch in
diameter. Though normally vertical,
they are frequently deflected at vari-
ous angles or even run obliquely. On
some blocks many little elevations ap-

Fiodbe 12— Scolithus in, miit Whitfield («p

ll'A///;. /</. > Sectional view.

pear about the mouths of the burrows, and the surface is covered with trails of
annelids I figure L3).

♦ Second Geol. Sur. Penn., E, L878, pp. L33 139
! Ibid., p. L38.

! /'■>./., p. 130.

gAnn. Etept. Wise. Geol. Sur. for 1877, 1880, i>. iv
i •• ologj of w i consin, vol. iv, 1882, pi. 2, •< I

PROCEEDINGS OF WASHINGTON MEETING.

HT^s

1* v

In a later publication * Professor Whitfield referred this form to the genus
Arenicolites, considering that while there might he some doubt as to the animal

origin of S. linearis of New York,
there was no question about the an-
imal origin of the Wisconsin form.

In 1881 Nathorst f referred to the
occurrence of Scolithus in northern
( HTiiiany, and he notes that Dames
expressed some doubt, in which he
himself shared, as to the organic
origin of the species. This doubt
arose from the fact that the tubes
were always parallel and never
transverse. Some specimens, how-
ever, he considered were undoubt-
edly worm tubes.

In 1881 Mr. U. P. James J men-
tioned a species referred to by him
as perhaps Scolithus linearis occur-
ring in the Cincinnati group of Ohio.
It is found on the under side of slabs
of limestone, and is described as fol-
lows:

1 , iV« ^.

SAV

'V.r.^t;

«* W -. -

Figure 13 — Scolithus woodi (sp.). (After Whitfield.)
View of surface ..1 slab.

" The fossils are shown in strong, raised
lines, from 1-21 to over }4 inch or more
wide, generally straight and parallel to
each other, but not always so."

Should the species prove to be distinct from S. linearis it was proposed to call it
S. dispar. This form is not a Scolithus in any sense of the word, but is probably a
species of Eophyton. The lines were produced by the passage of some organism
over the surface of soft mud (figure 14).

On the same page of the above publication a second species is described under
the name of Scolithus delicatulus (figure 15) :

" It consists of small, cylindrical stems, from half a line to one line in diameter, passing vertically
through the strata, irregularly arranged from % to % of an inch apart, mure or less. The appear-
ance is as if soft mud, forming the strata, had 1 n deposited gently around the plants without dis-
turbing their erect position. * * * < >n the under side the plants are broken off even with the
surface, or leaving small, shallow pits; oil the upper surface they arc elevated from half a line to
over one line."g

As we see, this form was considered a plant, but there can be no question about
its being a worm burrow.

In 1883 Professor T. C. Chamberlin|| figured Scolithus (?) woodi, Whitfield, as
Arenicolites woodi, saying he preferred this name, as the annelidan character of the
fossil had been determined.

* Ibid, p. 177.

fOn traces of some invertebrate animals and their paleontological significance (in Swedish and
French) : Stockholm, 1881.
X The Paleontologist, No. 5, June 10, 1881, p. 33.
I Ibid., pp. 33, 34.
|| Geology of Wisconsin, vol. 1, 1883, p. 128.

J. F. JAMES — THE GENUS SCOLITHUS.

In 1884 Professor N. H. Winchell, in a description of the geology of Rice county,
Minnesota * noted in the St. Peter sandstone great numbers of circular holes.
They are always perpendic-
ular, and can be traced 2j
feet by furrows on the sur-
face of the rock. It was at
first ascribed to the burrow-
ing of Cretaceous mollusks,
"but," Professor Winchell
says, " it is more likely to be
due to some marine vegeta-
ble, or to worm-burrowing
of Cambrian age." "It would
be the same as if a multitude
of horse-tail rushes or others
were growing in the bottom
of the sea when the sand
was accumulating and be-
came gradually buried un-
der the sand, and then were
imprisoned and fossilized,
their presence only being

Figure 14 — Eophyton (Scolithus) dispar, U. P. James (sp.).
(Original.)

evinced now by the cementation of the sand grains about their extei-ior, or by a
looseness of the same in their interior." The spots were only seen on upper surfaces
of the rocks, and were from £ to J of an inch in diameter.

This is also probably a species of Scolithus, possessing some of the characters of
linearis, some of woodi, some of delicatulus. Professor Winchell gave no name to the
form, but I propose to call it Scolithus minnesotensis.
It is probably this same form that occurs at Beloit
and other places in Wisconsin.

In 1887 Ami referred f to the existence of Sco-
lithus in Chazy strata, stating that although Scolithus
had been considered to indicate the rocks contain-
ing it were Potsdam, its occurrence at other hori-
zons shows the beds may be of a later age.

In the same year Messieurs Ami and Sowtercon-
cluded,J as a result of the examination of an exten-
sive scries of specimens from the Potsdam of the
province of Quebec, that S. linearis and S. cana-
densis were identical. The main difference between
the two, they concluded, was in the preservation,
the former occurring as casts of the burrows or
holes, while the latter were the burrows them-
selves.

In L890 Atreus Wanner referred? to Scolithus K|,,IUK ,.-, Scolithus delicatulus, V.
occurring in great abundance in the Hellam or P. James. (Origin

\ l Bx u

♦ Geology oi Minnesota; Final Report, vol. 1, 1884, pp. 656, 657.
fCanadian Bee. Bci., vol. ii, 1887, pp. 304-306.
| Ottawa Naturalist, vol. i, 1887, pp. 96, 97.
\ American Geologist, vol. \ . L890, pp. 35-38.

Gkol. Boc. Am., \ "i. 3, i-'i

42 PROCEEDINGS OF WASHINGTON MEETING.

Chickies quartzite of York county, Pennsylvania. He gave illustrations of the
tubes, flattened by pressure, and showed also an exposure of the quartzite with
great numbers of the tubes, often only | of an inch apart. No explanation is
given of their origin. This locality is tbe one from which the original specimens of
Haldemann came, and the form is doubtles the true Scolithus linearis.

In the same year Brainerd and Seely, in a description of the Calciferous of the
Champlain valley* mention the occurrence of Scolithus minutus, Wing. This is
considered a burrow, and the authors say :

"The fucoids, so far as we have seen, are not characteristic of any one division, though they
appear abundantly in various horizons of D. Further, Scolithus cannot be regarded as indicating a
Potsdam horizon, as the most abundant display we have ever seen i.- to be found at the bottom of
Division C, 600 or 700 feet above the Potsdam sandstone."

In 1890 Professor J. P. Lesley referred f to and figured Scolithus canadensis and S.
linearis. Both were considered by him to represent worm burrows in rocks of Pots-
dam age. He also says: "But the old idea that Scolithus characterizes and deter-
mines the Potsdam sandstone must be abandoned" (page 943). He then refers to
the work of Brainerd and Seely, quoting their remarks on Scolithus burrows in the
Calciferous, and he also mentions numerous localities in Pennsylvania where S.
linearis occurs, referring the rocks to the Potsdam. He also says that similar worm
burrow casts occur in the outcrops of Medina sandstone.

In 1890 C. T>. Walcott, in an account of the fauna of the lower Cambrian or
Olenellus zone,j states that Scolithus appears to range through the Cambrian. Bur-
rows in the Potsdam or upper Cambrian are similar to those in the lower Cam-
brian; and though it is not considered probable that the same species of animal
made the burrows in the two epochs, there are no means of separating them. All
the Cambrian forms are referred to Scolithus linearis.

In Bulletin No. 81 of the U. S. Geological Survey \ (just issued) Mr. Walcott gives
numerous references to Scolithus linearis and its occurrence in Cambrian strata.
From these it appears that numerous correlations of rocks from widely separated
localities have been made upon the evidence of this fossil.

During the field season of 1889 I found at various points in Wisconsin and Min-
nesota specimens of Scolithus. At Madison, Wisconsin, for example, the tubes occur
in abundance, penetrating the rock in all directions. Near Ableman I found one
specimen having the shape of the letter U, both ends opening at the surface;
otherwise it was exactly like the ordinary specimens of Scolithus linearis.

Near Merrillan, Wisconsin, on an isolated mound 11 miles southeast of the rail-
road station, an outcrop of sandstone occurs, part of which lias a columnar appear-
ance. When weathered, the columns stand out in relief and the top of the rock
has the appearance of a honeycomb with the cells sealed up. The same appear-
ance is presented by a sandstone 3 miles to the northward. These appearances are
probably due to Scolithus borings.

From the review here given it is seen that, originally described as a marine fossil
plant by Haldemann, the annelidan character of Scolithus was first pointed out by

♦Bull. Geol. Soc. Am., vol. 1, 1800, pp. 501-511.

-(•Dictionary of fossils of Pennsylvania ; Second Geol. Sur. Penn., P4, 1890, pp. 913-945.

| Tenth Ann. Rept., U. S. Geol. Sur., 1890, pp. 003, 604.

I Correlation papers ; Cambrian : 1891, p. 447.

J. F. JAMES — THE GENUS SCOLITHUS. 43

Logan in 1S52. Since then some authors have considered it as possibly a fossil
plant, but the great majority recognize it as a worm burrow. Billings, in 1869,
was the only one to refer it to the sponges.

There have been described of the genus from North America the following
species :

Scolithus {Fucoides) shepardi, Hitchcock, 1833 (Triassic).

S. linearis, Haldemann, 1840 (lower Cambrian).

S. {Fucoides) verticalis, Hall, 1843 (Portage).

S. clintonensis (n. sp.), proposed for 8. verticalis, Hall, 1852, preoccupied (Clinton
and Medina).

8. canadensis, Billings, 1862 (Potsdam).

S. minutus, "Wing, 1877 (Calciferous).

S. tuberosus, Miller & Dyer, 1878 (Cincinnati).

S. (Arenicolites) woodi, Whitfield, 1880 (Potsdam or St. Croix).

S. delicatulus, U. P. James, 1881 (Cincinnati).

8. dispar, U. P. James (= Eophyton dispar), 1881 (Cincinnati).

S. minnesotensis (n. sp.,), Winched, 1884, described but not named (St. Petero).

The geological range of the genus appears from this list to be from the lower
Gambrain to the Triassic. 8. shepardi from the Triassic does not differ in any
essential respect from S. linearis from the Cambrian. It is impossible to separate
S. verticalis of the Portage from 8. clintonensis of the Clinton and Medina, or either of
these from S. linearis. As we have already shown, S. canadensis and S. linearis may
be considered identical ; while S. minutus from the Calciferous and S. woodi from
the upper Cambrian of the Mississippi valley may be said to be separable by no de-
finable characters. S. delicatulus from the Cincinnati differs from S. mi nut us only in
having the cavities of the tubes filled instead of being hollow. Finally, S. minne-
sotensis from the St. Peter is the same, so far as characters go, as S. linearis from the
lower Cambrian.

It cannot be considered as at all probable that the annelid living in the lower
Cambrian and making the perforations we know as S. linearis persisted in the same
form through all later geological periods into Triassic time. Mr. Walcott does not
think it probable that the same species ranged even through Cambrian time, to say
nothing of a much greater time-range. Yet he places forms from the lower and
from the upper Cambrian under the same specific name. On the same principle
we should unite all the species, in whatever geological horizon they may occur,
under one name, for there are no characters to distinguish one from another. But
this docs not seem advisable, and under the circumstances I would propose that the
geological position shall decide the name to be used. Thus, 8. linearis might be
applied to forms from the lower Cambrian rocks of the eastern United states; S.
canadensis to those occurring in upper Cambrian strata of the eastern United States,
and S. woodi to those from strata of similar age in the upper Mississippi valley; S.
mi nut a* might he t lie name f< »r t he 6 >rni in Calciferous strata ; S. minnesotensis might
be applied to the forms from the St. Peter, and 8. delicatulus to those in Cincinnati
rocks; S. clintonensis might be applied to those from Clinton and Medina strata, 5.
verticalis to those from the Portage, and S. shepardi to those from the Triassic. It is
probable, also, that a name should he given to forms collected from other horizons,
say S. arizonicus to the form from the Grand canon in Arizona.

Several objections may be urged against such an arrangement. One of these is
that ii robs the genus of all value as indicating the age of the rocks in which it

4-1 PROCEEDINGS OF WASHINGTON MEETING.

occurs. This is true. It deprives Scolithus, too, of any value as a means of correlat-
ing rocks of two different sections, one with another. This is also true, and so it
should be. Xo valid argument can be brought forward to justify placing the rocks
of two widely separated areas in the same terrane upon the evidence of such a form
as Scolithus — a form of indefinite character, of indefinable features, of perplexing
variability, and of wide time range. The use of forms of this sort as a means of
correlation is even worse than the use of lithological character. Time does not
permit mentioning the erroneous correlations resulting from the use of Scolithus, but
they are numerous enough.

A second objection urged will probably be the multiplication of names resulting.
Some will, perhaps, prefer to let Scolithus linearis do duty for all the forms if they
can be shown to be indistinguishable ; but this objection does not seem to me to be
a valid one. Dr. C A. White, in a paper read before the American Association for
the Advancement of Science last year and published in volume 39 of the proceed-
ings, in speaking of applying new names to fossils occurring in two different forma-
tions, says that " if a given formation is found to bear a fossil fauna the component
members of which, witli such exceptions as have been referred to (i. e., forms con-
sidered identical in two formations) are all unlike those of any other known fauna,
I think it admissible to treat the whole fauna as new and to give a new name to
each species" (p. 242). My own studies of Scolithus led me to adopt this method
previous to reading Dr. White's paper, and I have therefore proposed, as seen above,
to characterize the species of Scolithus upon the formation, and not, as has been
done at times, the formation on the occurrence of the species.

The paper by Mr. James was discussed by N. S. Shaler and E. W.
Claypole. Professor Shaler advised neglecting altogether the specific
names for Scolithus, since it is at best only a hole in the rock. He also
regarded Billings' observations on sponge spicules as valueless, because
anything so widely distributed as these spicules would be readily swept
into small crevices or openings, such as the Scolithus perforations. Pro-
fessor Claypole remarked that Scolithus persists to the present time.

The following paper was then read :

THE TERTIARY IRON ORES OF ARKANSAS AND TEXAS.
BY R. A. F. PENROSE, JR.

Contents.

Distribution of the Ores Page 44

Geologic Relations of the Ores 45

Nature of the Ores 46

Nodular Ores 46

Laminated Ores 46

Origin of the Ores 47

Conclusions 50

Distribution of the Ores.

The Tertiary iron ores of Arkansas and Texas as now found are hydrous sesqui-
oxides of iron, generally occurring as limonites or allied forms. They occupy a belt
of country running northeastward and soutbwestward through the southern part

BULL. GEOL. SOC AM

VOL. Ill- 1891 PL-

R. A. F. PENROSE, JR. — TERTIARY IRON ORES. 45

of Arkansas and the eastern part of Texas. On the northeast they commence a
few miles south of Little Rock, cross Saline river south of Benton and Ouachita
river between Arkadelphia and Camden, and reach Red river north of Lewisville.
Southwest of the Red river bottom in Texas they again appear in the border counties
of Bowie, Cass, Marion and Harrison, and around the upper waters of Sabine river.
Thence the belt bears southwestward across Angelina, Neches and Trinity rivers,
finally thinning out before the Brazos is reached. The length of this belt is over
300 miles ; the width varies from 1 to 50 miles. The ore is not found continuously
throughout this area but occurs intermittently, the ore-bearing areas being often
separated by much greater barren areas. The distribution is shown approximately
in plate 1.

Associated with the ores there ai'e often found beds of sandstone, representing
local areas of sand indurated by the percolation of ferruginous solutions and often
locally mistaken for iron ore. Such deposits pass by abrupt gradations, both
vertically and laterally, into loose sands.

With the exception of the iron ores and the sandstones, all the strata of the
region are of a loose, incoherent nature, and therefore these factors have been
largely instrumental in controlling the topography of the country. The strata are
all either horizontal or dip by almost insensible gradations toward the Gulf of
Mexico. They have suffered considerably from erosion, and the usual topography,
where the harder materials are absent, is almost flat or gently undulating in sandy
hills. Where the ore and sandstone are present, the region is much more broken
and is composed of abrupt hills and ridges, flat on top and sloping off rapidly
toward the creeks and river bottoms. Though these hills are rarely more than
from 100 to 300 feet above the surrounding drainage, they are in marked contrast
with the usual Tertiary topography, and are locally known as " mountains." Their
form has been regulated by the harder strata, namely, iron ore and sandstone, which,
resisting erosion better than the associated clays and sands, have protected the beds
immediately under them, while those above them have generally been largely and
sometimes altogether removed. As a result of this erosion, the iron ores as well as
the sandstones usually cap the hills, and the heaps of broken rock give a rugged
character strongly contrasted with the usual sandy or clayey Tertiary surface of the
Gulf states. Occasionally a covering of sand or sandy clay still overlies the ore
beds, and in such cases the ore is seen only where it crops out on the slopes, form-
ing a rocky rim around the hills or along the slopes of the ridges. Besides the ore
and sandstone on or near the tops of the hills, similar beds are sometimes found
below, cropping out on the lower slopes.

As the ore is of only local extent, so the flat-topped hills are only local,
while elsewhere the less resistant strata have been eroded down to the surrounding
level.

Geologic Relations of the Ores.

The geologic position of the ores is in the Eocene scries of the Tertiary, and
probably in or below the ( Jlaiborne horizon of thai series. Two principal divisions
in the Eocene contain noticeable quantities of ore, though more or less iron is
characteristic of the whole series. The lower one is in the greal section of sands
and sandy clays which form the central partof the Eocene; the upper one is at
the top of the Claiborne glauconite thai overlies these }>v<\*. The lower deposits
are extensively developed in both Arkansas ami Texas, and comprise by far the

PROCEEDINGS OF WASHINGTON MEETING.

larger part of the iron-ore belt. They are not confined, to one individual stratum,
but occur in various positions in the beds of which they form a small yet charac-
teristic part. The upper deposits are extensively developed in Texas, in the area
south of those just mentioned, especially in Cherokee, Smith, Rusk, Nacogdoches
and other counties. The correlatives of the latter deposits have not yet been iden-
tified in Arkansas, and it is somewhat doubtful whether they exist, though certain
iron ores in glauconite have been found in the valley of the Ouachita. The eastern
extension of the Texas ore-bearing glauconite, however, is probably to be looked
for in northern or western-central Louisiana, an area in which the iron ores have
not yet been thoroughly investigated.

Nature of the Ores.

Though the ores occupying the lower and upper positions just mentioned are
much the same in chemical composition, being in both cases hydrous sesquioxides
of iron, they differ considerably in their physical character, and may be classified
under the two headings of nodular ores and laminated ores. The former represents
the lower horizon ; the latter represent the upper or glauconitiferous horizon.

Nodular Ores. — The nodular ore is characterized by the nodular character of the
component parts of the ore beds, though it also occurs in mammillar, stalactitic or
botryoidal masses. The nodules are often, and in some places generally', hollow
representing geodes, and vary from a fraction of an inch to several feet in diameter.
They are frequently cemented together by ore, or by a ferruginous sandstone, form-
ing a more or less continuous bed, while at other times they occur loose in the
enclosing sands and clays. They generally are partly filled by a yellow, brown, or

Figure 16 — Ideal Section showing the Mode of Occurrence of the nodular Ores.
1 = Sands and sandy clays ; 2 = Ore beds.

red clay, and sometimes by a ferruginous ochre. They vary from yellow or brown
to almost black in color, and the geodes are usually lined on the inside by a brilliant
black gloss. Sometimes the outer part of a nodule is an amorphous mass, while
the inside exhibits the fibrous character of certain hydrous sesquioxides of iron.
The more solid nodules show a concentric structure, the individual layers being
often separated by narrow spaces which generally contain more or less earthy
matter. Frequently this variety of ore occurs in 1 teds separated 1 >y horizontal layers
of sand or sandy clay, the individual beds varying from a fraction of an inch to
many feet in thickness. The accompanying ideal section (figure 16) represents a
characteristic mode of occurrence of the nodular ores.

Laminated Ores.— The laminated ore is of a rich chestnut-brown color, often resin-
ous in luster. It usually has a more or less laminated structure, which, though it
sometimes blends into a massive variety, is generally composed of thin layers
varying from a sixteenth to a quarter of an inch in thickness. The laminae are
separated by narrow spaces, often containing a gray clay, and are frequently coated
with a black gloss. The ore occurs in horizontal beds from one to three feet in
thickness, sometimes continuous over many acres, elsewhere in isolated patches.
It is composed of masses which are fiat or slightly concave on top, and bulging or

R. A. F. PENROSE, JR. TERTIARY IRON ORES. 47

mammillary below. It directly overlies a bed of glauconite, which varies from
thirty to forty feet in thickness and which is underlain in turn by a sei'ies of sands
and clays. It sometimes crops out on the immediate summits of flat-topped hills,
but is more often covered by from one to twenty or more feet of sandy clay, which
represents the remains of the overlying strata, as already described. The glauconite
bed contains considerable quantities of iron pyrites and numerous Claiborne
fossils.*

Sometimes thin seams of iron ore occur in the glauconite below the main ore bed,
but they are usually small. Between the main ore bed and the overlying sandy
clay there is a layer of dark -brown hard sandstone varying from one to six inches

"-i1 i"i^» »';

Figure 17 — Ideal Section showing the Mode of Occurrence of the laminated Ores.
1 = Sands and sandy clays ; 2 = Ore bed ; 3 = Glauconite (greensand).

in thickness and averaging probably one and a half inches. The ore crops out on
the brinks of the hills, forming a protruding rim or crown and often covering the
slopes with large masses that have broken off from the main bed. The accompany-
ing ideal section (figure 17) represents a characteristic mode of occurrence of the
laminated ores.

Origin of the Ores.

In inquiring into the origin of the iron ores of the Gulf Tertiary it is necessary
to consider the conditions surrounding the deposition of the great series of alter-
nating sands and clays which comprise the mass of the strata. That they are a
littoral formation is proved by the character of the organic remains enclosed in
them ; by the not infrequent occurrence of pebble beds (especially in Arkansas) ;
by the. lateral blending of marine and brackish water or lagoon deposits ; and by
the rolled and rounded character of many of the shell fragments, shaped as if by
continued beating on or near a sea beach. Again, the frequent occurrence of ex-
tensive beds of lignite at various horizons would indicate conditions of deposition
which permitted numerous ready transitions from marine to land or coastal-lagoon
environments. Such conditions doubtless gave rise to large areas of swamps and
shoals along the coast of the Tertiary embayment, probably not unlike those now
seen in places on the coasts of Florida and Louisiana, and around the lower part of
Sabine river in Texas. Into these basins the waters from the land drained and
probably often remained in a semi-stagnant state for considerable periods, under-
going a considerable evaporation.

The rocks forming the coast of the Tertiary Gulf of Mexico all contained greater
or less quantities of iron-bearing materials : The glauconite of the upper Cretaceous
of Texas and the Paleozoic and pre-Cambrian rocks to the west of the Cretaceous
area were a ready source of iron to the circulating waters ; while the Carboniferous
and Silurian shales and sandstones of central and southwestern Arkansas supplied
an important quantity of iron to the waters tributary to the Gulf. These waters,
draining into the coastal lagoons and swamps, were subjected to active oxidizing

*Kee Aiifielo Heilprin: The Koeene Mollusea of tin- State of Texas, ProC. Acad. Nat. Sci. I'liila.,
part III, Oct-Dec, L890, pp. 393 W6.

48 PROCEEDINGS OF WASHINGTON MEETING.

influences which eventually caused the precipitation of the soluble salts of iron
contained in them, and this action may have been greatly facilitated by the con-
siderable evaporation that probably took place.

The form in which the iron was precipitated depended on the local conditions
surrounding each area : Where iron in the form of sulphate came in contact with a
reducing agent, or wdiere other salts of iron were in the presence of sulphuretted
compounds derived from decaying organic matter or from other sources, then the
iron was often deposited as sulphide (iron pyrites) ; otherwise the iron might have
been laid down as either oxide or carbonate, or as glauconite. Subsequent segrega-
tion doubtless often assisted in the accumulation of the ore in certain areas.

Though the large bodies of iron ore now found in the Tertiary area are in the
form of oxides, there is decided evidence that they were originally segregated as
carbonate and sulphide. It is very probably, however, that the original deposition
may often have been as oxide, and that the forms of sulphide and carbonate were
produced during a subsequent segregation into nodules and layers.

The nodular ores already described have doubtless been largely derived from the
oxidation of an impure carbonate of iron in the form of the so-called clayironstone.
This material is of common occurrence throughout the Tertiary strata, though it is
usually seen only in protected places, such as in well-borings, in some creek bluffs,
and in other places in which it has not been exposed for a sufficiently long time to
undergo oxidation ; while, where it has been so exposed, it has been converted to a
more or less hydrous sesquioxide. The strongest evidence of this derivation of the
nodular ores is that in many places they can be seen in the actual process of tran-
sition, and it is not an uncommon occurrence to find masses of the as-yet unox-
idized clayironstone forming the kernels of the nodules. Moreover, the masses of
ore are often composed of aggregations of angular geodes, the angles of which are
so arranged that if they were brought together they would form one solid mass of
geodes. In most of the unaltered clayironstone masses there are numerous
shrinkage cracks, and it seems probable that the shape of the angular geodes has
been regulated by the directions of these cracks, which caused the mass to be more
or less divided into separate parts, each part afterward funning a separate geode.

The clay already mentioned as often occurring in the geodes doubtless represents
the residual insoluble product left after the oxidation of the clay-ironstone.

This mode of derivation is by no means confined to the Tertiary ores : It is de-
scribed by many writers in iron ores in various Paleozoic horizons. Dr. T. Sterry
Hunt* explains the formation of the geodes by the gradual shrinkage in the
transition from carbonate to oxide of iron, causing a diminution of volume equal to
19.5 per cent of the original mass. The transition progresses from without inward,
forming layer after layer of oxide, often separated by spaces as a result of contrac-
tion, while in other nodules the whole shrinkage is represented by the central
cavity alone. Hence sometimes the concentric nodules ; at other times the hollow
geodes.

The laminated ores, which are especially well developed in Cherokee county,
Texas, appear to have been derived largely from iron pyrites, assisted probably in
some cases by carbonate of iron and glauconite. As already stated, the laminated
ore directly overlies a large glauconite bed in which iron pyrites is of common
occurrence. In some few places, when natural conditions have protected the beds
from atmospheric influences, it is found that the pyrite is especially abundant at

* Mineral Physiology and Physiography, ls.so, p. 262.

II. A. F. PENROSE, JR. — TERTIARY IRON ORES. 40

the top of the glauconite bed and immediately below the overlying clayey sand.
Here it occupies t lie same position as the laminated ore elsewhere and is frequently
associated with sands and clays which often contain lignite. The thin layer of
sandstone found overlying the laminated ore frequently contains masses of lignite
completely converted to iron ore, and these prohahly represent the alteration
product of the lignite originally associated with the pyrite.

The following section at the McBee school-house, near Alto, Cherokee county,
Texas, shows a case of the original condition of the iron pyrites :

1. AVhite sandy clay varying from 10-30 feet.

2. Ferruginous sandy clay becoming indurated at base 1 foot.

3. White sandstone with a cement of profusely disseminated iron

pyrites 1-3 inches.

4. White sand with lenticular masses of lignite (1 to 4 inches in thick-

ness) and many disseminated particles of iron pyrites, passing

below into a plastic greenish-brown clay •'! feet.

5. Dark-green glauconite at hottom of section

This section appears to represent the original condition of the strata before the
formation of the laminated ore. That ore usually occurs immediately above the
glauconite represented in number 5 of the section, but here the same position, that
is, above the glauconite and below the sandy clay, is represented by some four feet
of sandy and clayey strata highly charged with iron pyrites. This mineral, by its
oxidation, forms sulphuric acid and sulphate of iron, the latter sooner or later be-
coming still farther oxidized and going into a hydrous sesquioxide of iron. It
seems probable that the combined action of the sulphuric acid and sulphate of iron
percolating down from the pyritiferous sands into the clay causes an interchange of
constituents, and that the clay is to a greater or less extent converted into iron ore.
This would account for the considerable percentage of alumina usually found in the
ore, and also for its laminated structure, a structure often seen in the unaltered
clay. The thin layer of sandstone, which has already been mentioned as capping
tin' laminated ore, is probably due to the induration of the sandy stratum imme-
diately overlying the clay by the peroxide of iron derived from the oxidation of

the pyrite. •

The shape of the ore bed is strong evidence of the formation of the ore by the

process just described: the upper surface of t he bed is usually flat, but the base of
it is very uneven and shows a series of bulging and receding mammillary forms.
These masses are often distinct from each other, but are closely assembled together
in a continuous or almost continuous stratum. The upper surfaces of the ore
masses are often concave, while the lower surfaces are convex, apparently pointing
to derivation bv t he downward percolation of the ferruginous solutions as already

described.

The glauconite itself may in some cases have assisted in the formation of the
laminated ore, hut its influence has probably been small. Glauconite is doubtless

an important source of iron in surface waters, and the ferruginous -"hit ions derived
from it may often be precipitated elsewhere and accumulated in considerable

beds of ore; but the case in question Ls one of the formation of brown hematite
in situ, and in such a process glauconite does nol seem, at least in the Tertiary area
of Arkansas and Texas, to have been so important a factor as the carbonate and
sulphide of iron.

VI] Bi n. Gi oi 3oi Vm., Vol. 3, 1891.

50 PROCEEDINGS OF WASHINGTON MEETING.

Besides the pyrite at the top of the glauconite bed, the same mineral is often
found in greater or less quantity lower down in the formation, and where it has
been oxidized it gives rise to masses and layers of hydrous sesquioxide. Carbonate
of iron in the form of layers or nodules or as a finely disseminated material is also
a common constituent not only of the special glauconitic formation in question)
but also of many other Tertiary glauconites of the Gulf basin, and by its oxidation
also gives rise to the hydrous sesquioxide. The ferruginous solutions derived from
the pyrite or carbonate often percolate through the glauconite bed and deposit thin
layers of brown hematite in joint cracks and along lines of 1 tedding, often giving
the impression that the ore has been derived from the oxidation of the glauconite.
In some cases the glauconite has undoubtedly supplied a part of it, but the fact
that the largest quantities of the sesquioxide are found in those parts of the glauco-
nite beds which contain most carbonate or sulphide of iron is strongly suggestive
of the greater influence of the last two as sources of the sesquioxide. The long-
continued action of sulphuric acid derived from the oxidation of pyrite, and of
carbonic acid derived from carbonate of iron, however, have had their effect in
decomposing the glauconite, and their influence is shown by the fact that where
oxidation has gone on in the pyrite and carbonate the originally green glauconite
is converted to a yellow or rusty, more or less indurated mass. Sometimes it is
hardened to such an extent as to be used for building stone. A similar alteration
of the glauconite takes place even where the sulphide and carbonate are absent, but-
less rapidly than where they are present. In fact, in the region of the ores asso-
ciated with glauconite in eastern Texas the whole formation presents a yellow or
brown surface exposure, while at depths of from a few inches to twenty feet or
more in the interiors of the hills the original green color is preserved.

( Inclusions.

From the above discussion the following general conclusions have been
reached:

1. That the iron ores of Texas and Arkansas occur mostly in two positions in the
Eocene series of the Tertiary.

2. That the ores were originally deposited in the form of oxide, carbonate and
sulphide contemporaneously with the associated strata, and that they were sub-
sequently segregated mostly as carbonate and sulphide.

3. That the ores as now found are the products of the oxidation of the carbonate
and sulphide, the nodular ores being derived from the carbonate and the laminated
ores from the sulphide of iron.

Professor I. ('. White was called upon to take the chair, and the fol-
lowing paper was read :

SANDSTONE DIKES IX NORTHWESTERN NEBRASKA.

BY ROBERT HAY.

At the meeting of the American Association for the Advancement of Science at
Ann Arbor in 1885, Professor A. E. Crandall read a paper on " The occurrence of
trap rock in eastern Kentucky," away from all centers of eruption. In the ensuing
discussion, Professor L. E. flicks, of Nebraska, mentioned a dike near Chadron, in

ROBERT HAY SANDSTONE DIKES.

northwestern Nebraska, which was likewise distant from eruptive centers, but
stated that the material was sandstone. Last winter, at the meeting < if the Geological
Society of America, Mr. J. S. Diller read a paper on sandstone dikes in California,
which, with its illustrations, forms a very attractive issue of the Society's memoirs.'"
Within a short time I have seen two sandstone dikes in northwestern Nebraska.
One is that referred to above as mentioned by Professor Hicks, which he had
already described to me. The second is only half a mile fn >m the first, and possibly
may be a continuation of it. I have seen the firston two different occasions, takinu
measurements both times; the second one was visited only once, on the same date
as the second visit to the first. On this occasion I was accompanied by Professor

. v

^*\s

Figtjee 18 — Sandstone Dike number 1.

Culver, who filled the chair of geology in the university of South Dakota. So far
as the measurements are concerned, Professor Culver is responsible as much as
myself. The general description he can verify.

The town of Chadron is situated on the line of the Fremont, Elkhorn and Missouri
Valley railway, and" lies immediately under the heights of Pine ridge, where the
I ia r«ler Tertiary beds of this region are seen over the softer clays and marls forming
the " manvaises terres," which, beginning under Pine ridge, stretch away inward
the north and east ami, with occasional cappings of the harder beds, become the
" bad la in Is" proper of South Dakota. Pet ween Chadron and White river, however.

♦ Bull. Geol. Soc. Am., vol. 1, L890, pp. Hl-442, pla. G-8.

PROCEEDINGS OF WASHINGTON MEETING.

there is but little of harder mortar beds, the deep ravines being almost entirely in
the softer marls and clays. In places they are cut down to Cretaceous shales, prob-
ably here of the Montana group.

Directly southward from the western part of the town of Chadron, and at a dis-
tance of a little over two miles, or just over the ridge (from which the entire valley
of White river and the labyrinth of "bad land" ravinesare visible), and just a little
to the left of the road running northward, is the first dike, or number 1. It is in the
upper part of a ravine, which joins many others near by. It is so inconspicuous
that it may be easily missed, yet was once much better developed than now and
had the name of the " natural wall." Notwithstanding this name, there is a very

Figure 10 — Eastern End of D;ke number 1.
Showing thai the dike * 1 i < 1 not teach the top pf the Muff.

common impression that it is the work of human art, and was made by ancient
Chadronites to corral the buffalo. But a wall it is, stretching straight across a
ravine whose width is only three or four feet greater than the exposed length of
the dike. It is said that early settlers saw it at least four feet high in the bottom
of this ravine.

The dimensions obtained in June last were as follows: Length of the wall (across
the ravine), 120 feet; average width, 8 inches; range in width, 6 to 10 inches.
There must he added to this thickness from five to ten inches for a vertical lam-
inated accompaniment which varies from 2', to 5 inches thick on each side of the
wall. Tlu- dike is almost perfectly straight, and trends N. 48° E.

EOBERT HAY — SANDSTONE DIKES.

The structure of the dike is such as fully to justify the term " wall." There are
both vertical and horizontal lines of fracture, the former being at right angles to the
line of the wall. Thus it breaks naturally into blocks, which are all rectangular.
The material is sandstone.

The wall is unmistakably a dike. When the exact age of these White river 1 teds
is determined, the age of the dike will be known. It does not on either side reach
the top of the ravine, and a bluff of much greater elevation a few hundred feet away
shows no sign of its presence ; so it may be definitely regarded as having been
intruded before the completion of the deposit of the soft clays and marls. One of
the evidences of intrusive character lies in the structure of the laminated sheets on

Figure 20 — Dike number 2.

cither side of the dike. In these the lamina:' furthest from the dike are more argil-
laceous 1 lian those inside, and the inside laminse are decidedly grooved, with verti-
cal ridges, and grooves to correspond, on the Bides of the wall itself. The laminated
structure on either side is from 2\ to •"> inches thick, and separate laminse vary
from one-eighth to five-eighths of an inch in thickness.

Half a mile in a westerly direction is dike number 2. In general, i1 is similar to
number 1, but there are minor differences. It also crosses a ravine, which is nar-
rower than the other ; and the dike appears to be the cause of this, as it seems to have

checked erosion, particularly on the western side. Its exposed length is loo feet ;

its average thickness is nearly uniform at 13 inches. The vertical laminated

PROCEEDINGS OF WASHINGTON MEETING.

structure on either side has an average thickness of 3 inches. The blocks into
which the wall is broken are short in proportion to thickness, and many might be
called cuboidal. The stone, too, is harder than in number 1. The direction of the
dike is N. 70° E.

If the lines of direction of the two dikes be continued, they cross a little nearer
to number 1 than number 2, and at an angle (as seen from the above figures) of 22
degrees. Running these lines without surveying instruments, this angle was
obtained as 25 degrees. Considering the distance apart and the smallness of this
angle, it might be possible that the two exposures are really parts of one curved
dike.

Figure 21 — Dike number 2.
Showing characteristic "manvaise terre" erosion.

Professor F. R. Carpenter, of Rapid City, South Dakota, a fellow of this Society,
has had the following analysis made by Mr. Barnett, one of his assistants. The
analysis is of a piece from dike number 2:

Si02 77.S4

A1203 13.09

Fe203 1.26

CaO 3.41

MgO tr.

H20 3.20

98.80

ROBERT HAY SANDSTONE DIKES.

These dikes may be related to the phenomena of mud volcanoes, as they were
certainly intruded from below ; and they may be expressive of the closing period

Figure 22 — General View of Dike number 2.

of the Black hills uplift. Wedo not desire here to enter into this question, but sim-
ply contribute the facts for future study of what may fairly be called a new subject*

Mr. Hay's paper was discussed by C. R. Van Hise and J. E. Wolff.

Mr. Gilbert resumed the chair, and after announcements declared the
Society adjourned to the evening session.

Evening Session op Monday, August 24.

The Society reconvened at 8 o'clock p. m., the acting President, Mr.
G. K. Gilbert, in the chair.

Some announcements were made, after which the following paper
was presented :

SOME RECENT EXPERIMENTAL REPRODUCTIONS OF SCOTTISH MOUNTAIN

STRUCTURE.

BY HENRY M. CADELL, ESQ., OF BO'NESS, Scotland.

This paper was illustrated with colored charts, and was followed by a

paper of similar character, illustrated with lantern views, entitled :

MECHANICS OF APPALACHIAN STRUCTURE.

BY B \ii.ky w 1 1. 1. is.

The papers of Messrs. Cadell and Willis were discussed together by
.1. E. Wolff, Joseph he Conte, C. D. Walcott, and the authors.

♦ After the meeting the writer was informed by Dr. Hoist thai there are Bimilar dikes in Sweden,

and Professor Hill states that something of the s ■ kind exists in Texas, and there appear i" be

some in tin- "bad lands" of South Dakota.

56 PROCEEDINGS OP WASHINGTON MEETING.

A third paper was then presented, on —

MUIR GLACIER AND ITS VICINITY.
BY II. P. CUSHING.

This paper was illustrated with lantern views, and is published in The
American Geologist, volume viii, 1891.

The Society then adjourned.

Session of Tuesday Morning, August 25.

The Society assembled at 10 o'clock a. m. ; acting President Gilbert
in the chair.

Professor Edward Orton, in behalf of the special committee appointed
on August 24, presented the following report :

EULOGIUM OF ALEXANDER WINCHELL.

The Geological Society of America hereby puts on record the expression
of its profound sense of loss in the removal by death from its councils,
its service, and the honors which it has to bestow, of one of the most effi-
cient and influential of its founders, Dr. Alexander Winchell. Promi-
nent in all of the preliminary work that led to the organization, he has
been an office-bearer of the Society from the date of its establishment,
and at its last annual meeting he was made its president.

Our sense of loss is due to the fact that in the death of Dr. Winchell,
stricken down as lie was in the fulness of his productive power, geolog-
ical science loses one of its foremost representatives in this country.
Forty years of arduous and uninterrupted work stand charged to his
credit in the records of American geology. During this period the sci-
ence itself, in common with all other branches of organized knowledge,
has been greatly transformed. The older subdivisions have been deep-
ened and extended ; new subdivisions have been established. To all of
this progress Dr. Winchell was from the first an important contributor;
with all of it he kept abreast.

Dr. Winchell's first important work was done in stratigraphy and
paleontology. As state geologist of Michigan, be helped to work out. in
an important and interesting section of the St. Lawrence basin, the order
of the geologieal series, and he worked it out so well that from that time
forward he who runs may read. In his later years he took an active
part in the study of the unsolved problems of the Archean system, and

EULOGIUM OF ALEXANDER WINCHELL. 57

all of the problems, structural and historical, he has treated lucidly and
soberly and to the enrichment of our literature.

There is, however, another division of our science in which Dr. Win-
chell's untimely death will be most severely felt. Who among us is
prepared to treat with equal scope and breadth, with equal mastery of all
that has? been done by others in this abstruse field, the large questions of
cosmical geology — questions which, though requiring for their discussion
the methods and resources of other divisions of science, must always find
their most natural reference within our own domain ?

In the death of Dr. Winch ell we lose an accomplished and eloquent
teacher of geology, whose oral instruction has inspired many thousands
of educated men, in all professions and callings, with deep interest in
and profound respect for this division of knowledge, while his text-books
have marked a new departure in the elementary teaching of geology, to
the great and lasting advantage of the science.

To all this must be added his remarkable ability and success as a
popular expounder of the doctrines of geology. No man since the days
of the elder Agassiz has done so much to familiarize the more intelligent
portion of our American communities with the great deductions and the
established results of our science.

Another service, and one of incalculable value, though confessedly in-
capable of precise definition, Dr. Winchell rendered to us all in this line
of public exposition. Unquestionably the most important contribution
of our day to geological science is the doctrine of organic evolution, as
presented by Darwin and his successors. But the first enunciation of
this doctrine naturally awakened distrust and even bitter hostility
among a large class of our people, because of its apparent incompati-
bility with some of their most fundamental convictions and beliefs. To
disregard the sincere apprehensions of this great class, comprising as it
does so much of the moral and intellectual force of the body politic,
would be heartless. To mock at its fears, ill founded though they were,
would be worse. What worthier service to science and the community
than to disarm this hostility by showing that the evolutionary philos-
ophy, so far from degrading and dishonoring man, makes him in a
peculiar sense the head and crown of the creation? We are indebted to
Alexander Winchell more than to any other representative of science
for the rapidly growing liberality and enlargement of thought of the
more serious-minded portions of the community in regard to these ques-
tions. From the lecture platform, in magazine and review and news-
paper, as well as in more formal and permanent fashion. Dr. Winchell
stated and defended with marked ability, courage, and persuasive power

VIII— Bum.. Geol. Soc. Am., Vol. :i, l.v.ii.

58 PROCEEDINGS OF WASHINGTON MEETING.

this the most characteristic and far-reaching doctrine of modern geolog-
ical science. His last public service was in this very line.

In addition to the features of the life and work of our departed col-
league to which we have already called attention, at least by implica-
tion, viz, his breadth and largeness of view, his hospitality to new truth,
and his courage in advocating it, we must not fail to name the personal
qualities that have insured for him a lasting place in our affection and
regard. In his candor, his fairness, his courtesy, he approached the
ideal of the searcher for the truths of nature ; in his devotion to his
work he literally knew no limit, save that which the narrow house and
the long sleep impose upon us all.

To sum up in a word, Alexander Winchell's work constitutes an hon-
orable section of American geology, incorporated in its growth and built
into its foundations, and thus sure to bear fruit for all time to come,
while the spirit in which he did his work insures to his name honor and

regard on the part of all who knew him.

Edward Orton,

C. R. Van Hise,

C. A. White,

Committee.

I. C. White moved the adoption of the resolution b}^ a rising vote.
Dr. Charles A. White, in seconding the motion, spoke as follows:

For nearly thirty years it was my good fortune to feel assured that
my name had a place upon the list of Alexander Winchell's friends. We
each, unknown to the other, began our geological studies upon closely
related formations, and soon after the publication of my first papers he
called upon me at my home to confer with me upon the subject of our
studies. This was the beginning of our acquaintance, and from that
time until his death my esteem for him steadily increased.

It is not necessary for me to add anything to the eulogy that has
already been spoken of him, but I wish to avail myself of this oppor-
tunity to add my personal testimony to his virtues in a second to the
motion just made.

Professor Winchell was a man of strong personality, but he was also
strongly sympathetic. He not only possessed all the cardinal virtues of
the ancients — justice, prudence, temperance and fortitude, — but he was
kindly, generous and charitable. His love for his family and kindred
amounted almost to a passion, and yet his kindness of heart extended
to all with whom he came in contact. He was deeply and sincerely
religious, but bigotry was entirely foreign to his nature. He was delib-
erate and careful in 'forming his opinions, and once formed he held

KfLOOIUM OF ALEXANDER WINCIIELL. 59

them with firmness ; but in upholding them he never descended to per-
sonalities, and no word was ever uttered by him that left a sting on the
memoroy of his opponent, even when vanquished. He was wist? and
learned, a kind and true friend, an exemplary citizen, and, best of all, an
honest man.

The motion was unanimously adopted by a rising vote.

The first title on the printed program was passed over, and the follow-
ing paper was presented :

THE EURYPTERUS BEDS OF OESEL AS COMPARED WITH THOSE OF NORTH

AMERICA.

BY DR. FRIEDRICII SCHMIDT, OF THE ACADEMY OP SCIENCES, ST. PETERSBURG, RUSSIA.

(Abstract.)

One of the uppermost divisions of the Silurian system of the state of New York
and western Canada, the Waterlime group, is characterized by a peculiar fauna of
large crustaceans, Eurypterus, Pterygotus, Ceratiocaris, etc. It has already been said
hy Sir Rhoderick Murchison that this fauna shows a great resemblance to similar
crustacean faunas of the uppermost Silurian strata of Great Britain, the shales of
Lesmahago in Lanarkshire and in some places near Ludlow, where the crustaceans
are associated with a small Lingula, the characteristic Plaiyschisma helicites, and
divers fish remains.

But still greater seems to be the resemblance of the American Waterlime fauna to
our Eurypterus beds of the island of Oesel, in the eastern Baltic, because the most
characteristic forms of both localities are two very nearly allied species of Euryp-
terus— the E. remipes of America and the E.fischeri, Eich., with us. Besides the
Eurypterus, we have a large Pterygotus, the P. osiliensis (aff. P. bilobus, Salt.), two
species of Bunodes, Eich. (connected with the English Hemiaspis), and a large
Crrittlortirlx, the C. niitlingi, similar to the C. maccoyanus of America.

Last summer a local collector, Mr. Simonsohn, of Wenden, in Livonia, found the
metastoma of the genus Dolichopterus, hitherto only known from the American
Waterlime ; and so the resemblance between the American and Russian eurypterids
becomes greater.

The most famous locality of our Eurypterus beds is Rootzikull, near Kielkond.
Here, besides the crustaceans, we havealso found fish remains— two cephalaspidean
genera, Thyestes, Eich., and Iremataspis, described some years ago by Eichwald,
Pander and myself. Now we have better specimens, which will be described soon
bv I>r. I. Rohon, of St. Petersburg, who has also lately described the first real fish
remains of the Lower Silurian, from the greensand at the base of the Silurian, at
Wessiks.* These Eurypterus beds, consisting mostly of yellow dolomitic flagstones,
are overlain by thin marly deposits, only a few inches thick, filled with small

♦ Some of the Eslonie country people at Rootzikull know hoM to get the Eurypterus out of the
limestone, and Mr, Simonsohn, who now spends every summer there, will be ready !•• furnish geol-
ogists wil li gi ""l B] [mens.

GO PROCEEDINGS OF WASHINGTON MEETING.

specimens of Leperditia (L. angelini), Platyschisma hdicites, Sow., and small scales of
fishes mostly belonging to the genus Ceelolepis of Pander.

With us the Eurypterus horizon forms the base of our uppermost Silurian stage,
K, according to my arrangement of our Russian Baltic Silurian in Estonia and the
island of Oesel,* and can be followed all over the island, from west to east, at the
boundary line between the stages J and K, the former corresponding to the Wenlock
of England and the Niagara limestone of North America.

The Eurypterus beds are overlain by a yellow limestone or dolomite containing
Stromatopora, Favosites, Syringopora reticulata, Labechia conferta, and other corals (but
not Halysites, which is restricted entirely to lower horizons of the Upper Silurian), be-
sides Murchisonia cingulata and allied forms, Orthoceras inibricaium, <>■ angulatum, and
(). (jiijmitiii, Ilionin prism, Megabmus gothlandicus, Meristella didyma, Leperditia grandis,
and other fossils. In the southern and southwestern portions of Oesel there fol-
lows a band of gray limestone with Atrypa prunum, Spirifer elevatas, Chonetes stria-
tella, numerous specimens of Tentaculites and Beyrkliia, peculiar forms of Galymene and
Proetus, and in some places with a profusion of spines ( Onehus) and scales ( Tachylepis,
Pand., or Ghelodus, Murch., Oniscolepis) of fishes described by Pander in 1856. This
gray limestone, which is known among the northern German erratic bowlders as
the Beyrichia limestone, I regard as the highest beds of Oesel, though actual super-
position has not been observed. Both the gray and the yellow limestones corre-
spond very well with the Ludlow of Great Britain. The yellow limestone containing
also Eurypterus fischeri is very clearly recognized on the eastern side of the Swedish
island of Gothland, near < testergarn, and also on the Dniester in Podolia (southern
Russia), from which locality the Eurypterus fischeri was originally described.

With regard to my Silurian country of Oesel, I have no reason to enter into the
Hercynian question, because, as already stated, our uppermost Silurian strata cor-
respond exactly to the typical Ludlow of England. Our Silurian is unconformably
covered by the middle Devonian (" Old Red sandstone "), since in the east the
Cambrian and lower Silurian strata are situated directly below the "Old Red
sandstone," just as in the west they lie below the upper Silurian deposits.

The purpose of this communication is to attract the attention of American geol-
ogists to the striking resemblance of the fauna of our Baltic Eurpterus beds to the
Waterlime fauna of North America, and to express the hope that our cephalas-
pidean fishes, or something like them, would be some time found in this country.

In coming to America it was my wish to become more intimately acquainted
with the different Silurian stages, and especially with those adjacent to the Water-
lime group. ;'. e., with the Onondaga and Guelph limestones on the one side and
the Tentaculite limestone on the other. It would perhaps be possible to find other
connecting links in the development of life in both countries.

Lately I have had the opportunity of seeing the Waterlime and the Tentaculite
limestone at Oriskany falls in the state of New York. Both deposits together cor-
respond very well to our uppermost eastern Baltic stage A'. But, beyond this strik-
ing resemblance of the Waterlime crustacean fauna and thatof our Eurypterusbedst
I cannot yet compare strictly the other deposits of my uppermost Silurian zone in
this country. That will perhaps he possible after returning from our long excur-
sion, when I shall have perhaps the opportunity of seeing more of the Silurian
strata in the United States and Canada.

*See Quar. Jour. Geol. Soc, Nov., 1882, p. o!4.

A. PAVLOW — MARINE MESOZOIC FORMATIONS. 61

The second paper read was :

ON THE MARINE BEDS CLOSING THE JURASSIC AND OPENING THE CRETA-
CEOUS, WITH THE HISTORY OF THEIR FAUNA.

BY PROFESSOR ALEXIS PAVLOW, OP THE UNIVERSITY OF MOSCOW, RUSSIA.

As regards the Paleozoic system, comparative or systematic geology has recently
made great progress, thanks to the excellent work of American and European geol-
ogists ; the correspondence of stages in the two continents has been established, and
the history of the Paleozoic seas is, in its principal features, the same for the whole
northern hemisphere. The case is different for the Mesozoic beds, especially for
those that close the Jurassic system and begin the Cretaceous. A kind of separat-
ism is observed in them : In the Anglo-Parisian basin and in part in Germany the
upper stage of the Jura is called by the name of Portlandian, and the Cretaceous is
held to begin with the Neocomian ; in the southern part of France, in Spain, and
in the Alps it is the Tithonic stage that tops the Jurassic, and the Tithonic in its
turn is overlain by the Berrias ; in northern England the boundary between the
two systems passes through a series of beds called the Speeton clay ; in Russia, the
name of Volgian stage has been created to designate the upper beds of the Jura
and the lower beds of the Cretaceous. Every country claims at this epoch its pe-
culiar geologic history, and the geologists of the various countries are busy describ-
ing the peculiarities of the beds deposited at that epoch. But what has become of
the vast ocean of the globe as it then existed ? Do we know the faunal history of
that ocean, a history independent of the local episodes spoken of in describing
these stages? What has become of the cephalopoda, the ammonites and the
belemnites, our faithful guide in the parallelization of the Mesozoic beds? These
are the questions that have long interested me, and I am happy to be able to com-
municate to this distinguished Society some results of my studies.

I shall try to be brief. I am convinced that the separatism of which I spoke is
not a consequence of the minute comparison of these stages, but rather a result of
the lack of comparative study, of the absence of a well concerted synonymy of the
species, and of the incompleteness of researches on the development of the faunas.
I have undertaken this study for belemnites and the ammonites, and the results
which I am going to set forth will demonstrate, I hope, its importance for strati-
graphic questions.

I had at my disposal, in my studies, a large collection from Speeton and Lincoln-
shire, by Mr. Lamplugh, the collections of the museums of York and Scarboro, some
forms from the South Kensington Museum and from the museum of the Jardin
des Plantes at Paris, and a large collection of fossils preserved at the museum of
Moscow.

In studying minutely the characters of the belemnites of the groups Excentrici and
Absoluti, and of the English group Oweni, which arc the most numerous in the beds
spoken of, I was able to distinguish amongthem three great brandies, each develop-
ing in a certain direction. The neighboring species that enter into these branches
pass insensibly into one another, so that the limits between them are more or less
arbitrary, while in the case of the typical forms they are perfectly well distinguished.
The most interesting fact from a geologic point of view is that these branches, in
the various countries, pass through beds developing in a parallel manner, and we
observe iii England and in Russia that the same phases of development appear

PROCEEDINGS OP WASHINGTON MEETING.

almost simultaneously ; and, vice versa, a certain phase of development indicates a
certain geologic epoch, as if it were a single fauna developing in some particular
direction and presenting some local deviation of small importance, such as the
predominance of this or that species and the comparative rarity of another.

Figure 21— The Development of the belemnitic Fauna at the End of the Jurassic and the

Beginning of the Cretaceous.

I now proceed to characterize these hranches, whose relations are indicated in
the accompanying diagram. The first comprises the greatly elongated forms, such,
for example, as have been described by Phillips under the name of Belenmites obelis-

A. PAVLOW MARINE MESOZOIC FORMATIONS. 63

cus, B. parrectus, etc. I add to them some other species and designate that branch
by the name of Porrecti. It commences in the Callovian by smooth forms without
ventral groove ; in the Oxfordian and the Kimmeridgian we find the same elon-
gated form with a short ventral groove below ; while in the upper Kimmeridgian
these belemnites have a ventral groove which passes from one end to the other.

The second Branch comprises the thicker and less conical forms. It begins in the
Callovian by Belemnites spicularis, a form almost devoid of a groove, which in the Ox-
fordian gives rise to B. oiveni. The latter is gradually transformed into B. magnifieus,
in which the groove or ventral flattening is very distinct and occupies about one-half
of the rostrum (guard). All the belemnites mentioned are common in Russia and in
England in the successive beds from the Callovian to the Kimmeridgian. B. mag-
nifieus gives birth to B. absolutus, the culminating form, which is widely spread and
very common in the upper beds of the Jurassic of Russia. I designate this branch
by the name of Magnifici.

The third branch, which I call Explanati, is the most complicated. Starting from
a Callovian branch, Belemnites subextensus, we see three sub-branches (twigs) devel-
oping each in its own direction. One comprises the thick-set and obtuse forms (B.
kirghisensis, B. lateralis and B. russiensis), while the other begins by B. breviaxis,
which is modified into B. e.rplanatus, and this in turn passes into B. subquadratus
and a kindred species, B. explanatoides. The third sub-branch begins by B. panderi,
which is transformed into B. troslayanus, the predecessor of B. mosquensis. I am
now convinced that B. panderi, and perhaps some allied species, exist in America,
where they are known under the name of B. dermis. As in the old world, so in
America, they characterize the boreal provinces of the Jurassic sea. The history of
the development of this sub-branch is the most interesting. In northern England
these forms are developed continuously up to a certain horizon, namely, the summit
of beds D, called Portlandian, but which are also considered by some geologists as
lower Neocomian. Above this horizon, in the beds C, these forms disappear
abruptly, and are replaced by belemnites of quite a different origin, B.pistxMrosbris,

B. jaculum, and other representatives of Hastati, which appear simultane* >usly. Mr.
Lamplugh, during several years of assiduous research at Speeton, found only two
specimens belonging to the preceding group. But already in the upper part of beds

C, and above these beds, the Hastati become less and less numerous, and we find
once more the belemnites exhibiting the characters of the Jurassic group Explanati,
but they are the more or less distant descendants of the Jurassic forms.

The Explanati were evidently dwellers in the boreal part of the Jurassic sea. They
are known in Russia, in northern England, in North America (Queen Charlotte
islands and Dakota). They are also found in France and in southern England, but
they are rarer in those regions. The Hastaii are the southern forms. They are
wide-spread in the Alps, in southern Europe, in the Caucasus, in India, and in
Madagascar. Thus we observe at Speeton, at a certain horizon, the invasion of the
southern fauna in the northern sea, and the replacement of the boreal fauna by the
southern fauna. But the predominance of the southern fauna was nut of long du-
ration ; already in the upper Neocomian, and perhaps also in tin- middle, conditions
changed, and the descendants of the boreal forms come to regain the dominion of
their ancestors. In Russia the history of the faunas is less complicated, because
the southern colony did not exist there, except in the Crimea.

The history of the belemnites which 1 have just set forth is only an example
affording us a glimpse into the history of the Mesozoic seas at the epoch in question.

64 PROCEEDINGS OF WASHINGTON MEETING.

Certain groups of ammonites present no less striking examples, proving that a
climatic change took place in the seas of middle latitudes in the northern hemis-
phere at the beginning of the Cretaceous period. The characteristic cephalopoda
of the lower Cretaceous of middle Europe are well known. They are especially the
belemnites of the group Hastati, the flat belemnites, the ammonites related to the
group of Olcoslefanus astieri, the representatives of the genus OlcodiStus, and some
hoplites.

As regards the belemnites, we know already that they are southern forms. Fix-
ing our attention on 0. astieri, and its kindred, it is not difficult to see that it is a
southern form. We know it in India and in South Africa [A. aiherstoni), and the
British museum contains a very good specimen from South America. In Russia
we know these forms in the Crimeo-Caucassian region. In northern England
they appeared with the Hastati, to replace the boreal fauna, and to inaugurate the
typical Neocomian. The same thing might be said of the representatives of the
genus Olcodiscus and of some hoplites characteristic of the Neocomian. Thus the
study of the cephalopoda of the upper Jurassic and of the Neocomian demonstrates
that the forms are the same in central and eastern Russia, in northern England, in
Germany, and, in part, in southern England and in France ; that in the last two
regions the fauna presents a mixed character, the boreal forms being there found
together with the southern, the latter becoming more and more numerous as we
go southward. The boundary separating the two faunas does not always remain
the same. Certain epochs may be pointed out when the southern fauna advanced
northward, driving back the boreal fauna, which afterward resumed its sway. This
complicates the series of the beds which we are studying as well as their history
and we are often embarrassed in regard to the establishment of the exact corre-
spondence of the beds. But, on the other hand, we recognize horizons common to
the two great regions of the globe, and we are in condition to establish the strict
correspondence of the beds and to decipher the geologic history of the whole world,
provided we do not neglect the systematic paleontologic studies which indicate the
development of the important groups of the animal kingdom, suchas the belemnites
and the ammonites.

I have demonstrated that an interesting change took place in the physio-geo-
graphic conditions in a vast region, extending from eastern Russia to England. It
cannot be said that this was due to a local oscillation of sea-level. Not only is this
true, but the same forms of cephalopoda are found in the Jurassic and Cretaceous
beds of America. There, too, the two faunas, the southern and the boreal, may be
distinguished. The regions where these faunas meet (California, for example) pre-
sent difficulties to the observer, but they promise at the same time to yield a uni-
form and general classification for all countries, and to render intelligible and simple
the general history of our globe — that mysterious history which thus becomes more
and more attractive.

American geologists have before them the same scientific problems that engage
our attention in Europe. Their solution will be speedier and easier if we work
together. This suggested to me the idea of setting forth before you the direction
and some of the results of my studies. Our science knows not the artificial bound-
aries that separate nations, nor will it recognize natural boundaries, such as
oceans. The history of our globe has for a long time been the common work of all
nations and of all peoples, just as the globe itself will one day be the common heri-
tage of humanity, one and united*

*For further details, see Bull, de la Soc. des Naturalistes de Moscow, 1891.

/ /

H
D

~«^

■a

o«i

r»*

<"S

<-*>*

Cr> *

05
ft*

IS"

1— ^■■W

f^W

^13

(— •
05

i 1

<*>

^ k, £>

■">»

P
CD

•>

b
h

<§

•

0 '

i**

— -

r— '

GERARD DE GEER QUATERNARY CHANGES OF LEVEL. 05

The third paper read was —

QUATERNARY CHANGES OF LEVEL IN SCANDINAVIA.
BY BARON GERARD DE GEER, OF THE GEOLOGICAL SURVEY OP SWEEDEN, STOCKHOLM.

Although I have not had sufficient time to prepare an elaborate lecture, I have
thought it appropriate on the present occasion to place briefly before the Geological
Society of America a synopsis of our present knowledge in regard to the Quaternary
changes of level in Scandinavia, inasmuch as there are yet prominent geologists
who deny the existence of continental upheaval. The conditions found in Scandin-
avia, however, seem to afford good evidence of such changes. Moreover, this
seems to be the very time to place before you for comparison the analogous phe-
nomena in northern Europe, since so extensive and excellent investigations in
relation to Quaternary changes of level in North America are in progress just
now. And finally, it was my good fortune, immediately before leaving Sweden, to
complete my observations in such a way that it has been possible to give a general
view of the question and to present a somewhat detailed ,map of the changes, so far
as southern Sweden is concerned.

It has been long known that raised marine deposits with an arctic fauna occur
over the latest moraines in Scandinavia, and in most text-books they are said to be
found as high as 500 feet in Sweden and 600 feet in Norway ; but exact determina-
tions of the uppermost marine boundary itself have not been given, thereby allow-
ing too much latitude for speculation in regard to the cause of the present high
altitudes of these deposits. It is true that the eminent French physicist, Bravais,
half a century ago came to the conclusion that two elevated rock-terraces in north-
ern Norway examined by him are not horizontal but descend toward the north, the
upper one more so than the lower ; but his opinions have been doubted more and
more, and several geologists, even from Scandinavia, are less inclined to believe in
an unequal upheaval of the earth's solid crust than in changes of the level of the
changeable sea.

In Sweden no such rock-terraces as those of Norway, which are visible for miles
and miles, are found, nor are there, as a rule, long, continuous beaches; for the
wooded country is very hilly, so that it is not easy to connect the beaches and find
out whether tin- changes have been unequal or not. It seemed probable, however,
that the upper boundary of the marine deposits might be synchronous at the dif-
ferent localities, and I have, therefore, since 1883, attempted to determine altitudes
as often as an opportunity was offered. This assumption I have recently been able
to substantiate by the observation that the maximum of depression did not occur
quite simultaneously with the ice-covering, but somewhat later, as shown by chan-
nels cut through the summits of terminal moraines by glacier rivers coming down
from the ice-border at about '.)."> per cent of the height of the upper marine bound-
ary. Hitherto I have seen such channels of erosion only about the northernmost
extension of the terminal moraines on the map, just in the vicinity of the Norwegian
frontier; but it is probable thai they occur in many other places, and, if so, it will
be possible more accurately to determine the level of the sea at the margin of the
receding land-ice. At present it is already evident that at the maximum depression
no ice could, at least in southern Sweden, obstruct the synchronous formation at
all points of the uppermost beach.

IX— Bull. Geol. Soc. Am.,.Yol. :i, 1891.

G6 PROCEEDINGS OF WASHINGTON MEETING.

The method which I have adopted for determining the marine boundary is as
follows: I first select on the topographic map hills of sufficient altitude to make it
certain that they were above the marine boundary under all conditions. They must
be mainly covered with moraine matter, in which the breakers usually leave the most
easily distinguished traces. The situation has to be open and the ground mod-
erately inclined, so as not to interfere with the action of the breakers. Finally,
such localities must be selected as are situated in the neighborhood of points
already leveled, from which I could start when ascertaining the level of the marine
boundary. This, in different places, is of a somewhat different appearance. At the
promontories it is often formed as a cut terrace with a more or less steep bluff, at
the base of which sometimes only the greater bowlders are left just as the bowlder
pavements described by Mr. Spencer, and when the erosion of the breakers has
been very strong the rock is laid bare up to the very uppermost marine limit. At
more protected points the limit is sometimes marked by built terraces and beaches.
In ascertaining the level of the cut terraces I have always taken that of their base,
while of the others that of their summit, which, in general, is a few decimeters
lower. In every locality the mean is taken of several points at the boundary, and
the probable error, I think, will hardly exceed one meter, being usually only a few
decimeters. Most of the points (now amounting to about 60 or 70) are determined
with good hand-levels, some with spirit-levels, and only two with aneroids.

The first points which I happened to determine were situated in eastern Scania,
in the direction of the strike of the old deformed geoid, so that the heights of the
different points were nearly equal, viz, some 50 meters. Somewhat more toward
the south I afterward obtained successively 48, 42, 37, 32 and 21 meters, and that in
quite open localities, in which are found well-developed series of sea beaches below
the marine boundary, while immediately above the same the moraine matter does
not show the faintest trace of any washing by the sea. It was therefore evident
that it is necessary to assume an unequal uplift of the land in this the southernmost
part of Scandinavia. This led me to the conclusion that not only were the obser-
vations of Bravais in the Altenfjord correct, but that in all probability the same
law would be found exemplified all over the Scandinavian peninsula. In order to
investigate this question further, I attempted in 1SSS to plot on a map, published
in the Transactions of the Geological Society of Stockholm for that year, such ap-
proximate determinations of the upper marine deposits in the various parts of
Scandinavia as were available at that time. I thereupon connected the various
points of equal deformation by lines, as Mr. Gilbert bad already done for Lake
Bonneville. For the sake of brevity, I named these lines iaanabases or isobases.

This first attempt to thus put together the facts showed already most clearly that
all the points could be grouped in one single system, all the higher localities appear-
ing in the central parts of the land and all the lower ones in the peripheral parts,
in the south as well as in the west, the east and the north, in such a manner that the
isanabases formed concentric circles. The phenomena, thus being of purely local
nature, can have nothing to do with general changes in the level of the sea. Fur-
thermore, as the highest marine deposits are situated in the central parts of the
land as high as 260-270 meters above the sea, it will be easily seen that the very
much reduced remnants of the original ice-sheet which could possibly exist when
the sea in late-glacial time reached so far could not — with respect to their local at-
traction— have played any role worth mentioning in the explanation of the raised
beaches ; and the more so, when the figures we get when starting in the calculation

GERARD DE GEER — QUATERNARY CHANGES OF LEVEL. 67

from the maximum ice extension during the earlier and greater glaciation are even
then about ten times too small. We are thus obliged to admit that these shore-
lines have been uplifted through a real continental elevation of the earth's crust.

During the last four years I have determined a considerable number of points, and
these have afforded good evidence corroborative of the opinions expressed in my
first paper. Thus the isanabases were found to conform with the limits of the
Scandinavian Azoic territory, and, according to the very latest determinations, not
only in a general way but also in many details, the isanabases, for instance, form •
ing a great convexity around the southern extension of Sweden as well as small
ones around several promontories. On the other hand, they form concave lines
around lake Wener, as shown on the accompanying map. Though not yet quite
settled, the case is probably similar with regard to lake Wetter, the second largest
lake in Scandinavia. These lakes, therefore, have not risen quite so much as the
surrounding country. This fact seems to indicate that our larger lakes were orig-
inally more depressed than their surroundings during an earlier stage of the ice
age, thus probably accounting for their formation.

The coincidence between the area of upheaval and the Azoic territory may pos-
sibly be explained by assuming that this territory, which is an old tract of erosion,
has also been one of continental upheaval which subsided during the ice age, for
the greater part perhaps in consequence of the considerable ice-load, again rising
after the release from the latter, though not to its former altitude. Before this rise,
several straits crossed the central portion of Sweden, and through these Yoldia
arctica and Idothea entomon certainly immigrated to the tracts around Stockholm,
near lake Mtelar. These straits were gradually uplifted above the sea-level, and
the Baltic sea became a true fresh-water lake. To this time belong probably the
beaches in open situation, although containing such fresh-water forms as Ancylus
fluviatilis, Pisidium, Planorbis and others, which have been found in Estland, Gotland
and Oeland by Messrs. Schmidt, Munthe and Holm.

As shown by peat-bogs, river channels, and deposits of littoral mollusks, all now
submarine, the rise of the land continued until some tracts, at least, were lifted to
about 30 meters higher than at present. Then a new continental depression com-
menced, the uppermost limit of which I have had the good fortune to discover
and to determine at some twenty points in southern Sweden. This limit is marked
in many places of level ground by unusually well-developed beaches and terraces,
below which marine deposits with a true post-glacial fauna — containing the species
characteristic of the kitchen-middens of Denmark — are found, indicating Salter and
probably somewhat warmer water than at present.

The post-glacial limit is situated in the middle portion of the country about 50
meters above sea-level, becoming gradually lower towards the peripheral parts
until no evidence of any upheaval whatsoever can be discovered. While this post-
glacial depression is of a special interest in that its maximum was probably con-
temporaneous with the beginning of the neolithic stone age in Scandinavia, it also
shows thai a depression has taken place which cannot be directly connected with
the ice-load. In the meantime, it cannot yet be decided whether this subsidence of
the land between the two upheavals has occurred even in the central parts of the
country ami has been proportionate to the amount of these, oris perhaps only a peri-
pheral phenomenon synchronous witli a continuous elevation about the axis of uplift.

The distribution of the deformation indicated by the raised beaches is shown in
t he accompanying map, plate 2.

68 PROCEEDINGS OF WASHINGTON MEETING.

Time will not allow me to proceed further in detail. I wish only to say that I
do not think we have yet reached the full solution of the difficult problem of conti-
nental elevation. On the contrary, this is not to be expected when we consider
that we have scarcely more than commenced a methodical investigation ; but I
think that it has been shown that we have good chances of reaching the goal by
the somewhat long but reliable way of induction.

The paper was discussed by T. C. Chamberlin, E. W. Hilgard, G. K.
Gilbert and the author.

The fourth paper presented was on —

THE " BLACK EARTH " OF THE STEPPES OF SOUTHERN RUSSIA.
BY PROF. A. N. KRASSNOF, OF THE UNIVERSITY OF CHARKOW, RUSSIA.*

Among the problems belonging both to geology and to geography, the study of
the Quaternary sediments, including the soils, is one that has for a long time at-
tracted the attention of the votaries of these two sciences. In fact, the soils, like
most of the other recent formations, have so great an influence on scenery, culture
and vegetation that to know their origin, properties and distribution is as important
for the geologist as for the geographer. This is the reason why I, a geographer,
have come to attend the Geologic Congress and to take part in the discussions on
the Quaternary sediments of the globe. The object of my communication to-day
is to lay before you some recent researches on the Russian soils, which bear some
relation to those of America, and which are of general interest.

In Russia the study of the vegetal soils, and especially of the "black earth," has
recently attracted the attention of geologists, and it is to this study that most of our
researches have been devoted. It is my purpose in the following remarks to make
you acquainted with the principal results of these studies.

It is well known that the soils of southern Russia differ greatly not only from
those of other parts of Russia but also of the other countries of Europe. Only the
Hungarian, and perhaps some of the southern Prussian soils, have some similarity
with our black earth, but these are far less characteristic than those of Russia.

This soil, which we call chernozem, or " black earth," has long been famous for its
fertility, its black color, and its wealth in organic substances of a very peculiar
character, different from those of our marsh lands. These properties have attracted
the attention not only of travelers and of the natives, but also of naturalists ; and,
toward the end of the last century, Pallas, and shortly after, Murchison tried to
explain the mode of formation and the cause of the fertility of the " black earth."
Pallas looked upon it as a sediment of marine origin, formed by algpe and other
organisms decomposed and petrified. According to him, the steppes of Russia were
but recently abandoned by the waves of the sea. It is hardly necessary to say at
this day that this hypothesis rests on no scientific proof. Neither are the soil itself
and the underlying ground stratified, as are all marine formations, nor are they
tocked with the fossil remains of sea animals. There is no proof that the sea covered
the surface of southeastern-central Russia after the retreat of the Tertiary ocean,
which took place at a remote date. It is not surprising therefore that though this

♦ Translated by K. Stein.

A. N. KRASSNOF THE RUSSIAN " BLACK EARTH." GO

theory found adherents during the first half of the century, it was soon replaced by
another.

This other theory, founded on the opinion of the people and set forth in a scien-
tific manner by Ruprecht in 1866, has recently been confirmed by stronger proof
furnished by Dokuchaef. It may at this day be regarded as accepted by most
Russian geologists. According to this theory, the chernozem is nothing else than
a vegetable earth formed by the roots of plants, which, in decaying, enriched with
organic substances the rock on which they had flourished. It differs from our soils
formed by this means only by its wealth in organic substances and in the mineral
salts that accompany them. It has nothing in common with the soils of the
marshes, because the humus of the latter has an acid reaction, while that of the
"black earth " is neutral ; moreover, it is not transformed into other substances by
desiccation, as happens with the soils formed out of peat. The substances of the
underlying rock or subsoil form the mineral skeleton of the " black earth," and
the relative quantity of organic substances in the vertical section of that soil be-
comes less and less as we go down, until at a depth of about two feet it becomes
zero. The " black earth " has been found on the most diverse rocks. Thus, neither
its structure nor its position has anything in common with the sedimentary forma-
tions produced under water ; and the remains of the solid parts of the graminacese
scattered here and there through the mass of humus afford another proof, of no
less weight, that this soil was formed by the roots of an herbaceous vegetation.
This theory, accepted, as I have said, by most Russian geologists, in these general
terms, leaves yet many questions in obscurity.

If you cast a glance on the soil map of European Russia you will see that the
"black earth " there covers a very limited space ; it is a black band that begins on
the Austrian frontier, and may be followed to the Ural. Both the northwestern
and the southeastern portions of Russia are entirely devoid of "black earth."
Ruprecht, who was the first to give a scientific exposition of the theory of the
formation of the "black earth " by the roots of plants, at a time when the theory
of the glacial period had not yet become general, set forth these peculiarities in the
following terms : The whole northern and northwestern parts of Russia, at the be-
ginning of the Quaternary epoch, must have been a sea ; on the waves of that sea
floated the ice carrying the erratic blocks found here and there in northern Russia.
The northern boundary of the " black earth " was the shore of that sea. Accord-
ing to him, the limit of the erratic blocks coincides with the northern boundary of
the " black earth." Thus the erratic blocks in the north and the Aralo-Gaspian
sediments (with fossils of mollusks still living in the modern Caspian) in the south-
west were by him regarded as proofs that at a time not long ago the greater part
of Russia was covered by the sea. Only the region of the " black earth " was then
dry land, covered, as at the present day, by steppes. At this time the " black
earth " began to be formed. " In fact," says Ruprecht, " how will you explain that
the region of the chernozem lias a characteristic flora whose representatives are
Wanting in the northwest and southeast of Russia? How will you explain this
depth and this wealth in humus of this vegetal earth, if observation shows that mi
the kurgans or mounds erected in the midst of the steppes by the nomads, most of
which are more than a thousand years old, then- is yet found only a layer of soil
a few centimeters thick? Finally, why do these soils of the northwest and south-
east, of recent origin, bear so trivial a flora, in common with Scandinavia and the
Ural, while the chernozem is so rich in characteristic forms? We cannot but as-

70 PROCEEDINGS OF WASHINGTON MEETING.

sume that the region of the chernozem, from the earliest times, since the end of
the Tertiary, was a steppe covered by a characteristic steppe vegetation under which
the chernozem was slowly formed."

But this view, which to the modern geographer may seem somewhat crude, could
find adherents only up to the day when the glacial theory became dominant among
geologists and geographers. At the present day, after the researches of our glacial-
ists, Krapotkin, Nikitin, and others, we know that the youngest formations bearing
erratic blocks are of the same origin in our land as in Germany ; that they are the
moraine of the Scandinavian glacier, the traces of which are found not only in the
region of Ruprecht's sea but farther southward under the " black earth," as well as
in the governments of Poltava and Voronesh. Professor Dokuchaef having at the
same time found several points where the " black earth " covered Caspian sediments,
it became necessary to give another explanation of the peculiarities of distribution
of the " black earth" than that given by Ruprecht. At the present day the expla-
nation given by Mr. Dokuchaef and his school is regarded as the most probable.

According to him, climatic conditions, as well as the character of the vegetation,
imparted to the region of the " black earth " its peculiar contours. The properties of
the "black earth," he says, depend on the relative age of the ground, on its sub-
soil, on the climate, on the relief, and on vegetation. But since vegetation, too, de-
pends on climate, the latter is to be regarded as the main factor in the formation of
this soil.

In fact, nothing but the vegetation of the steppes covered by herbaceous plants
can form the chernozem. Submerged and marshy ground forms and accumulates
organic substances of an entirely different character. Forests are incapable of
producing " black earth." Numerous observations show that everywhere under
the shade of forests there is formed a gray soil, made up of pieces of the size of a
walnut, containing not more than 2 to 3 per cent of organic substances. This soil,
having very considerable thickness, was observed everywhere beneath the forests
of Russia and Denmark, and a series of special labors were devoted to this subject.
Observation even shows that forests taking root on the " black earth" decompose
it and gradually transforms it into the gray soil peculiar to forests. Thus it is the
condition favorable to the steppe and its vegetation that presents the best combina-
nion of heat and humidity necessary for the formation of the " black earth." In
fact, the numerous excursions and analyses made by Dokuchaef and confirmed by
myself in central Asia and Turkestan bear out this idea with striking exactness.

By means of comparison of " black earth " specimens taken in various localities
of Russia whose relief and subsoil were analogous, Professor Dokuchaef has pre-
pared a diagrammatic map of the variations in the quantity of organic matter of the
"black earth." This map shows that in the eastern parts of the region of the
chernozem, in the provinces of Penza, Samara and Simbirsk, we find the soils most
rich in organic substances. Toward the northwest from this 2>art of the region
spoken of, in proportion as the climate becomes colder and moister the soil becomes
less rich in humus, and is gradually transformed into the vegetal earth or sod of
the north, or makes room for the soils formed by forests, which begin to domi-
nate beyond the northern boundary of the "black earth." The same thing may
1)0 observed toward the southeastern boundary of our region. There, too, the soil
becomes poorer in humus, but, according to Dokuchaef, it is the dryness of the
climate, unpropitious to the steppe vegetation, that prevents the formation of the
chernozem. Dokuchaef's map also gives a series of approximately concentric

A. N. KRASSNOF — THE RUSSIAN " BLACK EARTH." 71

bands, the isokumic bands, encircling the region richest in humus, where the " black
earth " contains as much as l(i per cent of organic substances.

These researches in European Russia attracted the attention of our geologists and
botanists, and soon it was learned that in the various parts of Asiatic Russia, where
the climatic conditions bear some resemblance to those of chernozem Russia, soils
had been found that were analogous if not identical with the "black earth" of
Dokuchaef. Thus in the Crimea, in the northern foothills of the Caucasus, in
Siberia, and lastly in Turkestan, on the northern slopes of the Thian Shan, " black
earth " was found varying in quality according to the climatic law of Dokuchaef.
Thus, too, the great Black-Caspian depression is nearly surrounded by a zone of
" black earth " varying in breadth and in richness according to the conditions of
heat and moisture, and accompanied by a nearly identical vegetation.

The question of the causes of the geographic distribution of the " black earth "
being thus solved, did not yet supply an answer to the question, still more interest-
ing from a geologic point of view : the question of the age of the " black earth."
Unfortunately there exist but very few observations on this point. The chemical
analyses of the " black earth," taken in different parts of Russia, show that the
organic substances of the chernozem are accompanied by a number of peculiarities.
The quantity of hygroscopic water, of phosphates and of ceoliths, becomes larger in
proportion as the relative quantity of humus increases. As these properties are of
great agronomic value, the zemstvos (or assemblies) of some Russian governments
undertook special investigations of these soils. The zemstvos of Nizhni Novgorod
and Poltava prepared maps of their soils, under the supervision of Professor Doku-
chaef. The detailed investigations made in those provinces yielded very interest-
ing results, a part of which are summarized in the appended tabic They showed
that even in the same climate and on the same geologic formations the qualities of
the soils may be very different, and that the relief plays an important part in this
matter. Thus, for example, Professor Dokuchaef at Poltava, and myself at Khar-
kof, found the following relations to exist between soil, vegetation and relief:

1. The highest points and those most cut up by crevasses and valleys are richest
in forests and in gray soils, and the number of forests increases in proportion to the
number of crevasses. On the contrary, the points of gentle, flat relief, sparely pro-
vided with deep cuts — in a word, poorly drained — are the region of the "black
earth" and of the steppe.

2. The qualities of the "black earth " vary with relative height. The highest
points of the steppe are at the same time the richest in humus, although the differ-
ence in height is only one to three hundred feet.

.'!. The regions of the gray soils, especially when they accompany the high banks
of streams, are skirted by a zone of intermediate soils formed of the " black earth"
half transformed into gray forest soil.

4. The vegetation of the less elevated parts, though composed of species peculiar
to the steppe, is less rich in characteristic forms than those of the relatively more
elevated parts; while the latter, despite its steppe character, contains several water-
loving forms, the former is rich in endemic tonus or forms common to it and the
Caucasus and its Alpine and sub-Alpine regions.

if we observe the relief of these provinces, we shall see very interesting phenomena.
Where the soils are covered by forest t hey overlie eit her ( Yetaceoiis rocky subsoils
or Quaternary clays, drained in all directions by gullies. Quite a different aspect
is presented by the level lands covered by the " black earth." There the ground is

72 PROCEEDINGS OF WASHINGTON MEETING.

often covered by marshes and by little lakes, sometimes round and very shallow.
The number of these marshes and lakes was formerly very great, but they have
disappeared before the eyes of the inhabitants. The brooks on these plateaus have
banks that are but little pronounced, and on following their courses you come upon
the steppe, where you can hardly trace the beginning of the brook. Beneath the
soil are found loessoid clays difficultly pervious to water.

What is true of these two governments, which are now well described, is true of
the whole surface of chernozem Russia. Nowhere does the " black earth " prevail
alone ; everywhere it is interrupted by islets of sand or of gray earth with forest,
and everywhere the size and number of forests depend on the character of the
relief; and wherever the loess prevails, there we see the steppe, the steppe marshes
and the " black earth." All this shows that the climate of this part of Russia is as
favorable to forest vegetation, which is detrimental to the " black earth," as to the
steppe, and that there are in the soil itself certain conditions which now are more
favorable to the forest, now to the prairie. The steppe, despite the dryness which
characterizes it, seems to be less well drained than the spots where the forests pre-
vail ; the latter seem to augment in number in proportion as the relief is rendered
less regular owing to the growth of the gullies, the number of which increases
with exceeding rapidity with the cultivation of the soil.

If these observations are confirmed in other provinces of Russia, we shall have
to suppose that we are witnessing an enormous phenomenon of drainage of southern
Russia, where the steppe and the formation of the " black earth " play a j)art inter-
mediate between the marshy, semi-lacustrine state of the postglacial epoch and the
forest epoch. Drained by the great rivers, the clayey and loessoid subsoils, imper-
vious to atmospheric water, in a climate of scanty rain, must have been covered by
a vegetation of herbs of semi-Alpine origin, which covered the highest points dur-

i ing the preceding epoch. As the forest enters through the moister gullies into the
center of the " black earth " plateaus it transforms by its roots the soil, little per-
meable to water, into gray earth, which, acting as a reservoir of atmospheric water,
allows the forest vegetation to occupy the surface of the steppe. In other words,
we see here what was witnessed, according to Nathorst's theory, in Europe at a

•more remote period, when the tundras of the postglacial epoch gave place to steppes
with antelopes, which in their turn were covered by forests during the historic
epoch.

But, in order to be sure that this view is correct, we still need observations on
the postglacial deposits of Russia, those loessoid strata, poor in fossils, so widely
spread over the surface of southern Russia, on the appearance of which the features
of the morainic landscape peculiar to northern Russia disappear. Yet before these
researches, which already occupy much attention, are completed, I desire to call
your attention to the analogy existing between the soil and the character of our
steppes and the American prairies. So far as it was possihle to me to study the
American literature on the subject, winch unfortunately is but scantily represented
in our provincial universities, I was struck by the resemblance existing between
the Russian " black earth " and that of the prairies of Minnesota and Illinois. It
may suffice, in order to see this resemblance, to compare my list of Russian analyses
with the American analyses. There is close correspondence between the climates
of the two countries as regards temperature and rainfall. Moreover, the history of
the evolution of the prairie, as traced by Lesquereux (who thinks that the prairies
are even now in the state of transformation from the stage of inundated, lacustrine

A. N. KKASSXOF-

-THE RUSSIAN "BLACK EARTH."

and marshy land to the stage of the steppe), the relations existing between relief
and soil and the vegetation of the prairies described by Engelmann, Whitney and
Winchell (who draw a picture, exceedingly like that seen in Russia, of regions with
loessoid soil, covered by prairie, with elevated spots, stony and drained and covered
by forest, whose domain becomes larger despite human culture1, the influence of
the climate analogous to the climate of the Russian steppes, the value of which bad
been formulated by Professor Dana —all this reminded me very forcibly of what I
had seen in my country. Moreover, the whole history of the continent, from the
Paleozoic downward, permits the drawing of analogies between the great valley of
the Mississippi on the one hand and the Euxine-Caspian-Siberian valley on the
other — these youngest parts of the two continents situated between the Paleozoic
regions and the mountains of more recent origin ; both were reservoirs of the
glaciers of the glacial epoch, and both had their epoch of .inundation.

In closing this essay I take the liberty of making a special appeal to those
American geologists who are interested in the Quaternary geology of their country
If it is possible to establish closer relations between Russia and America, the ques-
tion of the origin of the American prairies and of the Russian steppes will be
easier to solve. If it is possible on the one hand to find in America relations be-
tween soil, climate, relief, and vegetation analogous to those of Russia, as well as a
dependence on climate analogous to ours ; if the distribution of the ''black earth '
around the valley of the Mississippi shows the same peculiarities as that around
the Euxine-Caspian depression ; finally, if the hypothesis of Professor Lesquereux
is confirmed by more numerous proofs in Russia and in America, I hope the ques-
tion of the age of the "black earth" will be solved, and it may be decided more
positively whether most of the American prairies are merely a less advanced stage
of evolution than those of Russia. Allow me, then, to repeat the wish that the
geologists of these two countries may work together and in harmony for the solu-
tion of this question, the interest and practical value of which are beyond doubt.

The detailed results of Professor Dokucbayef 's observations on the " black earths "
of Russia are summarized in the following table, which is extracted from his work
on the Russian chernozem, pp. 353-372:

Thickness and Contents in Humus and hygroscopic Water of the different Soils of Russia.

Left Shores of the Volga and the Kama.

V. ,

Locality.

Thickness
(in feet).

Humus.

Hygroscopic

iNO.

Latitude.

Longitude.

water.

• >
.>

57° 00'
55 42
55 36
55 24
55 IS
55 IS
55 is
■V) 12
55 06
55 (10

47° 30'
50 12
50 48

50 00

53 30

53 30
48 42
50 oo

50 00
47 00

0' 8"
2 4

1 0

2 2

1.703%
11.313

7.788
L0.845
12.502
14.2 IS
1 1 .728
13.0±

7.360

5.432

:».724',

7.000

5.044

0.02!
7.011

s.200

7
8
9

2 (1

1 ;;

2 0

i ii

s.:;::>
8.142

3.273

X— Bum,, •■oil. Soc. \u., Vol. 3, 1891.

PROCEEDINGS OF WASHINGTON MEETING.

Left Shores of the Volga and the Kama — Continued.

Locality.

X".

Thickness.

Humus.

Hygroscopic

w ater.

Latitude.

Longitude.

54° 24'

51° 30'

1' 7"

15.42::',

Ki.597%

54 18

46 00

3 11

4.838

2.268

53 54

50 00

2 0

12.355

10.245

53 18

46 42

2 4

3.370

1.831

53 42

50 00

2 4

13.070

5.4(15

53 30

52 00

2 2

9.785

9.566

53 24

48 30

2 4

7.616

4.2: Ki

53 12

47 4S

2 1

10.4U4

5.178

53 06

50 ni i

0 Si

1.727

1.2! 10

53 06

49 L8

2 6

5.1 US

3.225

53 00

50 00

2 0

6.662

3.234

53 00

47 18

2 6

10.480

5.650

2";

52 48

53 30

2 4

15.013

5.033

52 48

53 42

2 4

14.551

4.707

52 42

49 54

2 9

3.458

:;.S7>4

52 42

49 54

2 6

2.762

1.800

52 30

53 30

2 0

11.933

5.: 122

52 30

52 24

4.-> 48
50 48

2 4
2 :;

5.293
6.701

4.485

52 24

49 42

0 8

3.815

2.842

52 24

49 42

2 0

11.582

9.5t)4

52 24

47 48

1 6

6.915

3.105

:;:;

52 18

47 36

1 2

6.662

5.144

52 12

53 36

1 4

6.073

3.234

52 1 2

47 36

2 0

10.378

5.440

52 06

51 12

1 li

10.033

4.557

52 i M i

46 24

1 3

6.445

51 48

52 48

1 11

2.432

2.721

51 30
51 30

4i ; 36
44 00

1 1
0 7

4.193

1.(122

2.178

51 is

44 42

0 9

4.218

2.320

51 12

46 18

44 4 s

1 11
1 5

5 325
9.105

3.526

50 54

51 1 54

46 7)4
46 54

2 0

o <;

4.799
2.769

51 1 7,4

4.", 18

1 :;

3.621

4.2(55

50 30

46 48

0 oh

3.030

1?)

Tract between the Volga and the Dnieper.

X! ,.

Locality.

Thickness.

Humus.

Hygroscopic

Latitude.

Longitude.

water.

48
4'.i
50
51
52

55° 30'
55 24
55 18
55 12
55 00

4(i° 36'
4(i 30
4(1 30

4(1 (to
40 is

0' 7"

1 0

0 8

2 3

1 0

4.077',

0.7S7

3.651

9.543

0.200

(?)

4.549$
2.397

3.940

A. X. KKASSNOF — THE KISSIAX " BLACK EARTH." 75

Tract between the Volga \\i> ihi: Dnieper — Continued.

Locality.

No.

Thickness.

1 1 umus.

1 [ygroscopic

water.

Latitude.

Longitude.

:.:;

V '1"
2 6

12.988$

19.171

6.829$

:.4

54° is'

46° 00'

(?)

53 54

46 •"-II

2 :;

7.704

4.012

51 i

53 12

46 06

2 2

4.523

(?)

57
58

(?)
52 30

(?)
45 48

7.400

2.000

1 4

15.079

(?)

5i' III)

45 00

1 ii

9.047

5.211

51 30

44 00

2 (l

10.544

4.425

51 30

44 00

12.040

4.966

50 06

43 06

1 9

2.072

3.129

50 00

42 48

1 :;

5.420

6.(101

49 36

42 54

1 2

1.45(1

0.027

49 18

42 36

l ii

1 .422

0.933

48 48

42 06

0 11

2.526

5.127

48 42

42 12

ii n.1,

0.908

1.081

48 06

4:; 42

0 4

1.081

1.135

55 54

42 36

1 1

.",.405

2.158

55 48

42 00

1 5

4.010

2.530

55 24

42 30

0 7

7.710

3.490

55 24

42 24

1 11

11.000

5.000

55 1 8

42 24

2 (i

10.080

4,500

55 18

42 24

1 (1

4.210

L.530

56 00

42 48

ii <;',

1.140

(?)

55 54

42 48

1 4

4.05:;

1.580

55 54

42 48

1 3

6.138

2.200

55 48

42 54

1 5

5.520

2.05H

55 42

42 00

1 (1

2.205

0.667

55 36

4:; 00

II s

5.010

•'.200

55 24

42 00

1 !l

7.100

3.400

55 30

4:; 06

2 2

10.400

(?)

:>rt 24

42 48

2 ii

7.170

4.000

55 24

4:; oo

2 10

9.877

3.871

55 1 8

4:; 06

2 7

14.707

5.400

55 1 2

4:; 06

2 S

L3.565

4.17H

55 00

4:; (in

I s

8.095

3.041

55 00

43 nil

1 (J

1 1 .554

3.801

56 06

42 18

0 Ii

11.010

0.860

56 00

42 48

o s

3.410

2.040

55 54

42 is

1 1

7.540

2.448

55 54
55 48

1 4

1 0

7.880

5.S50

(?)

42 24

(?)

55 42

42 30

0 0

3.910

•'.410

:w> 36

42 1 2

2 4

6.320

2.530

55 36

42 1 2

2 li

5.040

3.310

55 36

42 30

1 10

S.420

3.580

55 30

42 48

1 II

5.000

-.104

55 i"i

42 54

2 1

4.170

L.930

LOO

5 I 5 1

42 48

0 11

2.680

l.oin

lnl

5 ! In
5 1 42
54 36
5 1 30

(1 S
II I
2 0
:: o

4.000
2.51)0
7.21 hi
0. 110

102

0.440

Id:;

3.860

101

42 5 1

5.017

in:,

54 2 1

42 5 1

2 I

0.070

I .'■ H i! i

<l>

PROCEEDINGS OF WASHINGTON MEETING.

Tract between the Volga and the Dnieper — Continued.

Locality.

V, >

Thickness.

Humus.

1 [ygroscopic

.NO.

water.

Latitude.

Longitude.

106

56° 00'

42° oo'

0' b"

1.700',

0.920%

107

55 54 42 IS

1 0

3.770

L.070

108

55 36 42 00

0 0

3,. 050

1.770

109

55 24 42 12

1 2

3.7S4

1.835

55 00 42 IS

1 0

7.110

2.940

111

55 00 42 IS

1 2

0.000

(?)

112

54 54

42 24

1 1

5.490

3.490

113

54 48

42 24

2 0

4.900

2.970

114

42 30
42 36

1 S

2 S

0.080
9.030

(?)

115

54 24

4.100

116

54 24 42 36

3 0

10.110

6.051 1

117

54 12

42 48

2 1

10.370

4.477

lis

54 12

43 00

10.050

3.501

119

54 IS 44 IS

0 11

7.570

4.156

1 20

51 48

42 24

1 0

0.15s

4.340

121

51 3i ;

43, 30

1 s

8.276

4.729

122

51 IS
55 36

42 30
39 42

9.501
0.590

5.S40

123

0 4h

0.072

124

57 1 2

37 00

8.5±

(?)

125

50 30
56 00

3,7 30
38 00

0 11
0 0

5.100
1.035

L26

1.751

127

55 24

41 oo

I s

4.572

2.901

L28

55 IS

40 42

0 s

0.757

0.047

129

55 3d

41 30

0 0

3.9S0

3.146

L30

55 24

41 3,0

1 0

5.042

2.S51

131

0 4.',

1 10

0 5.1

1.430
S.S31
1.150

132

133

55 48

32 00

1.123

134

55 48

32 00

0 o.\

2.33S

2.0S3

135

55 48

3,2 00

1 2"

3.30S

2.013

136

55 48

32 00

1 3

9.796

0.093

137

55 01 i

3,0 30

0 s

2.1 OS

2.4S9

138

54 42

30 30

0 0

2.503

1 .850

L39

54 30

36 30

0 10

3,. 297

2.9S1

140

54 30
54 IS

1 0
1 4

6.782
6.205

3.732

141

30 00

4.110

142

54 IS

37 1 2

1 2

2.057,

3.734

143

53, 42

37 24

1 4

5.999

7.988

144

53, 30

3,0 3,0

3 4

7.025

11.093

145

52 30

30 IS

3 7

9.595

0.452

146

52 1 8

42 00

3 10

13.703

7.000

147

52 IS

42 00

3 S

1 L.616

13.470

148

51 30

39 30

2 5

9.14S

0.3,03

L49

50 3,0

40 24

2 3,

6.667

3.003,

150

54 .30

33 24

1 2

2.527

1 .031

151

54 24

33 00

0 10

1.0S4

1 .457

152

54 00

34 00

0 10

2.3.3S

2.0S0

15:;

54 IS

35 IS

1 2

2.542

4.S2S

154

53, 42

35 00

2 0

8.747

s.002

1 55

53 30

34 30

2 0

S.109

9.126

156

53 24

34 24

0 s

4.959

4.970

157

53 21

34 42

1 0

S.729

3.537

15S

53 is

33 42

1 5

4.599

2.154

A. X. KKASSNOK — THE RUSSIAN " BLACK EARTH."

Tract between the Volga \m> the Dnieper — Continued.

Locality.

No.

Thickness.

Humus.

Hygroscopic

water.

Latitude.

Longitude.

159

53° 24/

33° 42'

V 1"

5.265$

0.552%

160

53 00

33 48

1 2

4.176

5.153

161

53 00

33 12

1 1

:;.370

1.000

162

53 00

:;:; 42

1 2

4.7:.o

3.500

163

53 00

34 00

2 2

5.825

7.282

164

53 00

34 00

2 5

8.115

4.096

165

52 48

35 00

1 11

8.523

0.400

166

52 24

35 24

2 0

8.060

3.620

167

52 18

34 00

2 °

6.106

7.698

168

51 54

35 00

2 3

4.(107

2.170

169

51 48

34 54

2 0

3.812

5.635

170

51 45

34 36

2 0

7.301

4.000

171

51 36

33 48

1 :;

4.20S

2.747

172

51 36

33 48

2 3

4.81 1

4.452

173

51 36

:;:; 48

1 0

3.300

1.810

174

51 30

34 42

2 11

4.365

."..180

175

51 43

37 00

:; 1

1 1 .427

13.734

176

51 12

34 24

2 6

7.319

4.809

177

51 1 2

34 24

2 10

6.031

4.960

17S

(?)

7.050

5.002

179

50 00

37 00

2 11

4.451

5.980

180

48 00

37 oo

2 2

5.047

0.798

181

47 31

38 oo

1 s

7.0=b

10.610

182

53 00

33 12

(?)

3.655

1.770

183

52 18

29 54

1 0

1.556

1.713

184

52 00

31 00

0 10

2.705

1.020

185

51 48

31 12

1 4

1 .425

1.188

186

51 36

31 36

(?)

1.680

1.204

187

51 24

31 36

2 11

1.802

1 .237

188

51 18

31 30

2 11

3.522

: 1.0 12

189

51 36

51 27

:;:; 00
32 36

3.010

2.000

190

1 4

2.554

191

51 18

30 54

4 8

2.514

2.045

192

51 15

30 30

• > Q

• > O

2.800

1 .240

L93

51 06

29 30

:; 0

3.608

2.047

194

51 06
50 42

29 30

31 is

2.345

5.450

2.M95

L95

2 0

.",.068

L96

50 30

31 48

4 0

3.830

2.830

197

50 24

31 is

2 0

3.495

2.707

198

50 1 8

32 00

2 0

3.024

[99

50 12

32 42

:; 0

3.240

3.791

2(H)

50 00

30 L2

."> 5

4.570

5.4:: 1

201

50 oo

30 42

2 0

3.401

2.653

202

40 30

32 00

1 10

2.865

2.404

203

40 IS

31 30

:; 0

3.730

2.170

204

."id 36
50 39

34 is
34 is

4.141

ii.047

3.810

205

1 0

4.040

206

50 39

;;i is

1 11

4.2:; 1

5.510

207

50 42

34 12

2 0

5.400

2.350

20S

50 30

33 4 2

2 :;

:;.so4

2.2(17

200

50 30

33 21

2 6

7.5S5

2.550

210

50 is

33 24

:; 0

6.591

3.809

211

50 12

33 00

:; 2

6.425

4.407

PROCEEDINGS OF WASHINGTON MEETING.

Tract betwees hi Volga ami ink Dnieper — Continued.

X.i.

Locality.

Thickness.

Humus.

Hygroscopic

Latitude.

Longitude.

water.

212
213
214
215

50° IS'
50 00

49 00
48 30

32° 18'

33 54

34 (10
33 1 2

2' 9"
3 2
3 0

2 0

5.70'.i',
8.786
8.519
3.892

3.280$
6.880

10.254
2.050

Tkaci between the Dnieper ami the Dniester.

Locality.

No.

Thickness.

Humus.

Hygroscopic

water.

Latitude.

Longitude.

216

50° 1'4'

28° 12'

0' 0"

0.964.$

l.oi :>',

•'17

50 24

5(1 12

28 00
27 48

1.29S
2.5 ±

0.701

— 1 /

21S

2 7

2.S00

219

50 06

27 36

1 S

2.883

L.830

220

49 30

20 36

2 3

3.116

2.378

221

49 24

20 l4

2 0

5.107

4.502

222

50 (10

25 00

0 0.',

2.695

L.138

223

50 30

2:; us

0 9

2.855

2.050

224 *

49 24
49 48

24 30
27 48

3.368
3.514

2.753

225

2 11

! 901

220

49 30

29 no

2 11

4.372

2.209

227

49 12

29 IS

4 2

2.331 i

L.501

22S

49 1 2

29 IS

3 11

2.809

1.632

229

48 42

27 30

3 10

5.902

4. 078

230

48 30

27 42

4 0

5.035

3.116

231

48 24

28 12

2 0

3.887

3.409

232

48 is

28 is

2 11

0.102

5.285

233

47 48

28 00

5 /

5.9S0

3.820

234

49 00

25 36

2 o

2.822

2.800

335

48 15

26 00

2 5

3.729

3.087

236

48 mi

20 12

3 0

5.718

3.267

237

20 DO

30 oo

1 2
4 s

0.230
4.912

4.580

23S

48 30

2.457

239

48 42

30 18

2 0

5.816

3.273

240

48 42
48 42

30 IS
30 42

1 .870

3.070

1.533

241

2 0

1.805

242

40 00

31 HO

2 11

2.i>77

3.594

24:;

48 00

20 30

3, 0

3.457

4.914

244

48 00

28 30

3 4

5.437

4.25:;

245

47 42

30 IS

(?)

5.756

4.646

240

47 24

30 12

(?)

6.274

4.463

247

47 12

30 on

'V)

::.222

3.300

24S

48 30

32 51

:; o

3.215

5.126

249

47 54

27 12

2 s

12.247

7.930

250

40 54

27 42

2 0

7.190

7.393

251

47 00

32 oo

1 s

1.990

3.876

A. N. KRASSNOF — THE RUSSIAN "BLACK EARTH." 79

NORTHERN I OAST OF THE BtACK, SlVASH AND AZOF SEAS ami THE BANKS OF nil, DoX.

Locality.

No.

Thickness.

Humus.

I [ygroscopic

water.

Latitude.

Longitude.

252

46° 48'

27° 48'

■_" 0"

5.074$

6.941 %

253

4ii 36

28 (in

1 9

3.559

2.470

254

47 00

2'.i 42

1 4

42)21

4.463

255

46 24

30 is

1 S

2.224

2.72s

256

40 12

2,2 24

■> •>

6.025

4.17S

257

46 12

22 30

2 2,

4.S44

8.370

258

40 48

22, (Hi

2 5

2.21 is

4.120

2.1! 1

46 42

24 2,1)

2 4

O.I SI)

L0.845

21,1)

4 7 06

27) IS

(?)

5.760

4.000

21 il

47 18

35 2,0

1 2

5.375

5.283

262

47 24

36 36

2 2,

4.(147

S.S02

263

47 12

2i ; 24

2 2

4.427

8.551

2(14

47 30

2,7 48

2 1

5.320

4.408

265

40 2d

48 42

0 11

4.701

5.930

266

47 4:;

2,'.) 54

0 9

1.969

3.424

21 17

4S 49

41 mi

1 2,

2.022

2.507

Caucasus, Land of the Kuban Army, vm, Crimea.

No.

Locality.

268

200

270

271

272

274

275

270

277

27S

270

281 1

281

2S2

283

284

285

286

287

288

289

200

201

Latitude. Longitude.

•io
42
43

42
42,
42
42
44
44
4-")
40

45
45
45

45
4--)
45
46
4-")

15
45

II
44
44

00'
24

IS
00

42
12
42
20
20
24
is

00
00

00.

44°

2!)

27
38
2,7

42'

2,0

27 DO

2,1 i

2,5

2,2

01)

Thickness.

0' 4.!"
1 2

1
1
1

0 11

1 2,
1 5
1 11

I 0

1 0

2 0
1 II
2
■_>

I)
1

s
1

0
■]
0

(?)

0 s

Unions

4.041',

4.227

7.001

4.768

4.777

9.266

5.586

7.S20

7.42,0

4.204

5.431

5.1 10

4.020

4.012

4.024

5.707

5.086

2.0

3.261

4.4 IS

5.211

2. 70S

4.127

8.543

1 [ygroscopic
water.

2.10.V,

2.002

2.1 lis

4.406

2.24S

3.543

2.657

4.727

4.541 i

L.952

4.060

3.284

4.201
2.222
4.442
4.464
l.oio
1.220
2.983
6.370
3.820
0.05:;
5.472
4.781

SO PROCEEDINGS OF WASHINGTON MEETING.

hi discussing the paper, Professor E. \V. Hilgard spoke as follows:

I have been greatly interested in Professor Krassnof's paper, as I have studied
the American "black-prairie soils'" in considerable detail; and, on the whole, I
agree entirely with him in his conclusions as to the conditions under which such
soils may he formed. There is one conclusion, however, which he has only casually
mentioned, yet which is, according to my investigations, a conditio sim qua non. I
refer to the neutrality of the "black earths" as compared with the decided acidity of
peaty soils. The cause of this neutrality is the presence of at least a certain mini-
mum amount of calcic carbonate; and in its absence 1 think such soils cannot be
formed. The fact mentioned by him, that the chernozem occurs in the main in
the loess region only, assures me that the same condition is fulfilled in Russia. All
the " black-prairie " soils I have studied in this country are essentially calcareous
soils, usually overlying limestones or marly rock-, or. in the case of drift areas, cal-
careous gravels. The eminent usefulness of lime in soils is well understood, and
those in which it and the abundant products of organic decomposition are com-
bined might naturally be expected to he profusely fertile ; and this is notoriously
true of our prairie soils, as well as of the Russian "black earth" — it is as true in
California, where such soils are now in process of formal ion. as it is of the prairies
of the west.

I have heretofore inferred the calcareous nature of the chernozem from analyses
communicated to me by Professor Grandeau ; 1 am pleased to have the fact con-
firmed by Professor Krassnof. I do not, however, wish to be understood as assert-
ing that calcic carbonate alone can produce such soils without other concurrent
conditions, such as were mentioned in the paper, nor that such soils must neces-
sarily be effervescent with acids. All the essential effects of lime in soils are assured
by the presence of one or two percent of the carbonate, or even le>s ; which amounts,
when finely diffused, will not usually show effervescence with any degree of cer-
tainty, but suffice to produce characteristic lime vegetation, and to guide the held
geologist in the outlining of calcareous areas.

I cannot but express also my gratification at having these latest of geological for-
mations— the soils — introduced into the discussions of this Society. Their economic
importance certainly justifies it. but thus far their consideration ha- usually been
relegated to the chemical or agricultural societies alone.

Professor (i. ('. Broadhead said :

Never having had the pleasure of visiting southern Russia, I cannot, of course,
say anything of the region spoken of in so interestinga manner by Professor Krass-
nof; but some time ago I was interested in the "black earth" of those steppes
described in a volume of RSclus. I was forcibly struck with the resemblance to
our own " black-prairie soils." Now, I do not say that in certain regions these soils
cannot be found, but my own observation goes to show that there are well-marked
and extensive areas of such in the states of Illinois, Missouri and Kansas. In Illi-
nois the " black soil" covers the greater part of the counties of Moultrie, Macon
and Piatt, resting on either the drift or else the upper < !oal Measures. In Missouri
the "black soil" is found in Saline county, resting on beds of the lower Coal
Measures. Further westward in Missouri, in the counties of Cass and Jackson,
it rests upon the rocks of the upper Coal Measures. It is also well developed in
northwestern Missouri, where it lies upon the drift or else directly on rocks of

A. X. KRASSNOF — TIIK RUSSIAN " BLACK EARTH." 81

the upper Coal Measures. Westwardly, in Kansas, the " black so;l>" rest upon the
rocks of the upper Coal Measures. Limestones generally prevail in these regions,
being rather scarce, however, in the part of Illinois above named, as well as in
Saline county, .Missouri. 1 have been disposed to ascribe the origin of these soils
in a large measure to disintegration of calcareous beds. The areas in which these
soils prevail are also chiefly confined to the prairie regions and not to those areas
where trees seem to have always existed. They seem peculiar to treeless regions,
but may extend a little way into the adjoining woodland.

Remarks were made also by A. S. Tiffany, T. C. Chamberlm, Robert
I lav. and the author.

The following paper was read in the French language, and afterward
a resume was given in English by Professor Stefan Sihleano :

<)X THE EXISTENCE OF THE DINOTHERIUM IN ROUMANIA.
1!V PROFESSOR GREGOIRE STEFANESCU, of THE UNIVERSITY OF BUCHAREST, ROUMANIA.

I take the liberty of claiming, for some moments, your attention on a question in
which most of you will he interested, as it occurs for the first time in our science :
namely, the existence of the Dinotherium in Roumania.

Some rears ago the geology of Roumania was almost entirely unknown — I say
almost, because, although we had some vague notions and brief descriptions of cer-
tain isolated regions, theories were generally founded on deductions drawn from
the geological structure of the neighboring countries, or upon superficial notes given
by foreign travelers who had more or less rapidly run through Roumania.

The geology of this country figures also in Dumont's geological map of Europe,
but neither the enumeration of the geological systems nor their respective limits
are generally accordant with facts, as we can easily understand, since all Dumont's
materials had no other origin than that which I spoke of above. We have now.
by the work of some Roumanian geologists, and especially after the studies made
by the Roumanian geological survey, more complete and exact knowledge of the
geology of that country.

But it is not my intention to occupy you with the geological systems and with
their extension into Roumania. You will be able to form an idea of them by throw-
ing a glance on the twenty-four sheets of the geological map of Roumania published
by our geological survey, which contain about the half of all the country, and which
1 have sent to the secretary of the Geological Society of America. You may ex-
amine also the small geological map of the whole of Roumania thai I published last
year, and which I now have t he honor to present to the members of this learned
body. As you may see, the Tertiary and Quaternary systems are much developed
and extended in Roumania, and many fossil remains of the larger mammalia have
been found there, viz., rhinoceros, mastodon. t\rr\\ gazelle, antelope, ox, elephant
(especially Elephas meridionalis, E. anti quits and /•.'. primigenius), camel and, lately,
t he Dinotherium.

I received in L878 a fossil molar tooth found at Gaiceana, in the judet (districl of
Tecuciu. It was the last bill one molar of a Dinotherium, but it was-so large that

\l B eoi„ Soi , Am., Vol 3. 1891

PROPEKIUXGS OF WASHINGTON MEETING.

it could not have belonged to the usual I>. giganteum, as you may judge from the
following dimensions :

A.ntero-posterior diameter meters. . 0.12

Transverse " " . . 0.12

Height of the crown " .. 0.08

Height of the root " .. 0.14

Distance between the hills of the crown " . . 0.05

Thickness of the hills at their basis " .. 0.05

These uncommon dimensions should lead us to look at these remains as belonging
to another species than the usual I>. giganteum, winch may be named I>. gigantissi-
mum.

I went then immediately to Gaiceana for the purpose of studying the bed yield-
ingthe remains. Itconsists of a micaceous yellowish-gray sand, with small sheets
and concretions of sandstone of different sizes. This sandstone must have been
formed from calcareb-siliceous infiltrations evidently posterior to the imbedding of
the Dinotherium remains, as the tooth Avas deeply impressed in one of the concre-
tions, which had to be broken in order to take the molar away, and in which it left
a beautiful impression. The dip of the strata is low. and the strike is northwest-
southeast; they belong to the middle Miocene. I found there other and smaller.
molars, a part of the lower jaw. and the incurved symphyses, with small incisors

l .

Ffgtjrb 1\ — Section through Manzati Valley.
1 = Loess : .! = Moeene beds.

Twelve years later (in 1890) I became aware that at another point. /'. e., Manzati,
in the judet of Tutova, in a bluff which had been eroded by the rains, many hones
of a huge animal had been uncovered. I went there immediately, and found that
several persons had already taken parts of the head of a Dinotherium. The first
excavation which I made uncovered a portion of a jaw with two molars; but as it
was winter and the weather was very inclement. I postponed the investigation
until spring.

The fragments which I found on this occasion are very important, viz :

1. Tlie right branch of the lower jaw, with its five molars. This is almost com-
plete; only the symphysis and the ascending branch are deficient, and nevertheless
the length reaches 0.80m., its height at the second premolar is 0.30m., and it is
0.16m. thick.

2. A portion of the left branch of the lower jaw, with the two posterior molars.

■';. A fragment of the right branch of the upper jaw. with a portion of the palatal
bone and three molars.

(i. STEEANESCU — DINOTHERIVM IN ROUMANIA. 83

I went again to Man/.ati in the month of May and found other remains, viz:

1. Ten ril>s, almost complete, one of which was no less than 1.20m. in length.

2. An omoplat, which could not be taken away except in pieces, hut which I
measured in situ. Its transverse diameter was L15m. ; it was 1.05m. from the glen-
oidal depression to the posterior ridge ; the diameter of the glenoidal depression
alone is 0.25m.

The deposit yielding the hones stands on the right bank of a small valley near
the village ofManzati. The geological structure of this valley, running from north
to south, is as follows: In the lower part we find a succession of strata of more or
less fine micaceous sand, sometimes yellowish, elsewhere grayish, which alternate
with sandstone strata disposed in small sheets or concretions, dipping gently east-
ward. Upon these strata, which belong to the middle Miocene, lies unconformably
a heavy stratum, 25 to 30 meters thick, of a yellow or grayish loess, sometimes sandy
and more rarely containing clay. In the upper part of the Miocene strata many
cavities have been produced by erosion, which have been afterwards tilled by the
earliest strata of loess, containing small concretions of white marl and many frag-
ments of worn sandstone.

We now have, therefore, two regions in Roumania in which remains of l)iu<i-
therium have been found, Gaiceana and Manzati, and which must he added to the
other points on our globe in which geologists have found remains of this giant of

the Tertiary world.

Professor E. 1). Cope spoke upon the subject of the paper, reviewing
the character and distribution of Dinotherium ; following which a recess
was taken until 2 o'clock p. m.

A.FTERN00N SESSION, TUESDAY, AUGUST 25.

The Society reconvened at 2 o'clock p. in., meeting in two sections.
The papers relating to the Pleistocene were read in the second section,
meeting elsewhere in Columbian University, the proceedings of which
appear on a later page.

The first paper read in the main section was —

TIM: ELiEOLITE-SYENITE OF BEEMERVILLE, NEW JERSEY.

BY I Wll> I . K EM r.

[Abstract.]

The paper opens with a brief description of the other American area- of elseolite-
syenite i Montreal, Canada : Litchfield, .Maine: Salem and Marblehead, Massachu-
setts; Ma-net Cove, Arkansas) and gives a synopsis of the work which has been
done upon them. Reasons for suspecting the existence of an outcrop in the \A\
rondacks are stated. An outline is then given of the discovery of the Beemer-

M PROCEEDINGS OF WASHINGTON MEETING.

ville exposure and of the previous description by Professor B. K. Emerson. It is
shown that only the northern third of a dike three miles long had been treated.
Reference is also made to the associated basic rocks, already described by the
author, and they are stated to be identical with some peculiar dikes of which an
an ■Hunt by the author will appear in a forthcoming reporl of the Arkansas geologic
survey, where they are called ouachitite:

The extent and geologic relations of the Beemerville syenite are next taken up
in detail. The syenite comes out as a great dike three miles in length, running
northeastward on the contact between the Kittatiny (Oneida) conglomerate and
the Hudson River (Trenton) slates. It is 300 to 400 yards wide. The dike was
followed from the northern to the southern end; the rocks collected are described
from thin sections and chemical analyses. As principal results.it is shown that
normal elseolite-syenite forms the northern third and the southern extremity ; that
most excellent ebeoi ite-por] ihy ry occurs in the middle third; and that toward the
southern extremity the dike becomes much more basic, running down to about 41
to 4*J per cent Si02, and showing marked affinities with theralite. The normal
elseolite-syenite contains orthoclase, elseolite, cancrinite, sodalite, aegirine, reddish-
brown biotite, titanite. magnetite and pyrite. Fluorite has been detected by Pro-
fessor Rosenbusch in some specimens sent him, although overlooked by the writer.
Careful search failed to discover either eudialyte or eucolite. The elaeolite-porphyry
contains crystals of elseolite up to an inch in diameter. Almost at the same time
with its discovery, this type of rock was also found in Arkansas by the late J.
Francis Williams, with whom the writer was in active correspondence; and these
two are the firs! announcements of this rare species in the United States. The
rock resembles the Brazilian tinguaites, and has additional mineralogical peculiar-
ities to those mentioned above. The very basic rock of the south is worthy of com-
ment, and the remarkable absence of plagioclase from a rock so low in silica may

he emphasized.

A discussion of the associated basic rocks (ouachitites) follows, and some inter-
esting facts are brought out as to their relations with similar rocks elsewhere in

'lie world. Some new dikes are also recorded. The paper closes with a short

Lescription of the contact metamorphism. Acknowledgments are due to Dr. J.

Francis Williams, of Cornell University (recently deceased .and to Professor H.

Rosenbusch for valuable aid.

In the subsequent discussion -I. Francis Williams announced that
\Y. S. Bayley, * > t ' Colby University, had discovered elaeolite in the horn-
blende-syenite of Hawes from New Hampshire; and J. E. Wolff stated
that he had learned of basic rocks occurring in close association with the
Salem, Massachusetts, elaeolite-syenite. Further remarks were made by
G. II. William.-, on the general subject of the paper, and by J. E. Wolff
on related rocks recently examined by him in the Crazy mountains of
Montana.

R. T. HILL — THE TEXAS-NEW MEXICAN REGION. 85

The next paper was —

NOTES ON THE TEXAS-NEW MEXICAN REGION.
BY ROBERT T. HILL.

< 'onti nls.

Introductory page 85

The Baton-Las Vegas Plateau 8G

The Llano Estacado 87

The Edwards Plateau no

The Washington Prairies 92

The Rio Grande Bmbayment 93

Basin Deposits of the Trans-Pecos Region 95

1 haracter of the Basins 95

The Hueeo-Organ Basin 95

The Mesilla Basin. im,

The Jornado del Muerto Basin 97

The Eagle Plats Basin '.17

Valley of the Salt Lake Basin !i7

Basin of Mimbrea 98

Probable Basins of the Peeos Valley 98

The Volcanic Areas of eastern New Mexico 98

Introductory.

The present paper is intended to call attention to certain widely distributed
features of the western Texan and eastern New Mexican region not hitherto de-
scribed. The region treated embraces 1 he country west of the longitude and south
of the latitude of the Ouachita mountains (approximately corresponding with the
thirty-fourth parallel). The features discussed are mostly non-mountainous, and of
later age (Neocene) than the latest mountain uplifts.

I have previously shown that the salient topographic features of the region con-
sist of:

1. A series of modern and ancient coast and dip plains,* comprising strata ex-
tending from the ( lomanche to recent in age, which cover the eastern half of the
state, and collectively forming what maj be called the coastward incline. This
embraces the coast prairies (Pleistocene), the Washington prairies (Neocene), the
Eolignitic or forest region ( Eocene), the main black prairie (upper < !retaceous),the
Grand prairie (Comanche or lower Cretaceous), and the two Cross-Timbers (bases
of the upper and lower Cretaceous respectively). The Llano Estacado may be in
some respects classified with the coastward incline, hut for the present it may be
treated separately.

■_'. The central denuded region, including the denuded area now occupied by the

great rock sheets of the Paleozoic and early MesOZOic ( Led beds) of central Texas.

mostly dipping westward, which lie unconformably beneath the group of the coast-
ward incline and the Llano Estacado, and are exposed by their removal through

erosion

* Professor W . VI. Davis has objected to the use ol this term (Bull. 1 1. Soc. Am., vol. 2, L890, p.

>7 1 and substitutes the term "structure plain " I nasi 1 inch as there maj be many kinds of structure
plains, of which u dip plain is a specific kind, I continue the use of the term clip plain in preference
to the g< neric one proposed by him.

86 PROCEEDINGS OF WASHINGTON MEETING.

:;. The two great mountain systems which limit the region — the- Ouachita on the
north, ainl the Rockies and the basin ranges of the trans-Pecos region and northern
Mexico on the west : the first of which (the Ouachita system of Arkansas and In-
dian territory i is older than the plains of the coastward incline system against
which they were laid down. The second system is composed of the basin moun-
tains, which consist in part of the uplifted, folded and crumpled southern rock
sheets of the earlier of these plains, i. e., those founded on rocks of Cretaceous age.

4. Plains laid down against and of later age than the mountain folds and syn-
chronous in age with the later formations of the coastal series, including the Llano
Estacado, and the lacustral or basin sheets laid down between the mountains and
in the erosion valleys of the plains.

The Raton-Las Vegas Plateau.

It is the popular conception, founded upon the conditions about Denver and
elsewhere, that the structure of the plains of Tertiary and later origin is such as to
abut everywhere against and incline away from the mountains toward the present
eoasl and Mississippi valley, forming a suitable condition for the transmission of
underground waters derived from the mountains. This conception is a mistaken
one. so far as northern New Mexico is concerned : for south of the Colorado line the
western margin of the plains recedes away from the mountains eastward, and inter-
posed between the Llano Estacado proper and the Rocky mountains there is an
interesting topographic feature — the remnant of an older plane or Eocene land
area, the structure of which dips toward the mountain front.

For this great region of country in northern New Mexico, lying east of the true
Rocky mountains and east of the Llano Estacado. south of the Purgatoire and north
of the Gallinas, the name of the Raton-Las Vegas plateau may be used to give dis-
tinction from the true Rocky mountains toward the west and the Llano Estacado
toward the east. This district embraces the buttes and mesas known as the Raton
mountains, the Mesa de Maya, and many other remnants of a former plain, and in
addition the subsequent plains of erosion upon which the eminences stand and upon
which the Santa Fe railway is built from Trinidad to the Pecos. The cities of
Trinidad. Folsom and Las Vegas may be considered as bench-marks along the
northern, eastern and western boundaries respectively of this region, while Raton,
Springer, Maxwell and other points along the Santa Fe railway between the Purga-
toire, at Trinidad, and the Pecos an' located upon it. Its southern boundary is the
superb escarpment of the Canadian-Pecos valley, which runs eastward from the
Pecos, cast of Pecos, crossing near by to the Texas line. This escarpment, as shown
on the topographic map (Corazon sheet) of the United States Geological Survey, is
over L,200 feet above the Canadian valley, which it overlooks.

In traveling eastward from the foothills of the Rocky mountains at Las Vegas
hot springs (altitude, 7,01)0 feet) the profile of the Raton plateau east of Las Vegas
ascends for 13 miles to the breaks of the Canyon del Agua, where the escarpment of
I >akota sandstone of the Canadian-Pecos valley is reached. This is an almost verti-
cal descent of 1,200 feet to the ranch at its base, where the Red beds begin. This
precipitous wall extends irregularly eastward for 100 miles, forming the northern
wall for the Canadian-Pecos valley, in the lowest portions of which the streams of
the Canadian and Pecos flow over L,500feet below the summit of the plateau. This
valley-plain is irregular in outline and of enormous area. In it the'mountain drain-
age of the Pecos and Canadian first approach each other and then separate upon

R. T. HILT. — THE TEXAS-NEW MEXICAN REGION. 87

their lorn;- and different journeys t<> the sea, an mini the salients of the north western
escarpment of the Llano Estacado, which looms up in the distance like a majestic
wall. Language cannot describe the magnificence of the scenery here. Everywhere
is seen the grand results of profound erosion, by which the overlapping formations
(Dakota, Denison and Trinity beds) have been stripped from the horizontal Red
beds, which constitute the valley floor, and has left standing in the valley numerous
remnants of the plain in the shape of great circular buttes and mesas, such as El
Corazon, the Gavilan, Mesa Rico, Mesa Redondo, the big and little Huerfano, Mesa
Tucumcari and others, every stratum of their red, brown and white beds being
visible in horizontal hands for scores of miles.

The western border is the foothills or hogbacks of the eastern front of the Rockies.
The northern border from Trinidad to Folsom is the northern escarpment of the so-
called Raton mesa, the foot of which is followed by the Denver and Fort "Worth
railway. The eastern border is less conspicuous, for it is the haseleveled shore line
of the Llano Estacado formation.

This region possesses a diverse surface aspect, consisting as it does of various
erosion plains upon which stand great remnantal mesas of sedimentary and eruptive
rock sheets, like Raton mountain and Fishers peak — remnants of the atmospheric
erosion of Tertiary and Pleistocene time. The region as a whole, however, is a
series of stratigraphic plains produced by degradation from one hard bed of strati-
fication to another in successive steps from the Fishers peak basaltic sheet, which
caps the highest mesas, to the Laramie sandstones; from these to the calcareous
flaggy layers of the Colorado shales, as at Springer and Las Vegas ; and from these
down to the basal Dakota sandstone's with the white hand of the Trinity which
forms the foundation of the series, as in the Canadian valley and the accompanying
Corazon escarpment. The Red lied floor is finally reached, below the white hand
of Trinity sandstone, some 10,000 feet below the highesl summit of the old plateau.

The plateau or shoulder as a whole is a product, then, of the unequal erosion of
the sub-horizontal beds of the upper Cretaceous from the Laramie to the Dakota,
inclusive, which are here included between the Red lied floor and the Fishers peak
basalt. This erosion from top to bottom of the successive plains of stratification has
partially removed more than 5,000 feet in thickness of sedimentary strata; and
there is no evidence that the region has ever been submerged since Cretaceous time,
either during the Llano Estacado or the basin epochs mentioned elsewhere. In
fact, it was the stream-worked land whose del iris furnished much of the sediment
for the rocks of the last-mentioned periods. It is the remnant of a great plateau
(the Tertiary land) which existed around the southern half of the Rocky mountain
uplift before the Llano Estacado (Neocene) epoch, during which the larger mass of
the plateau was degraded or haseleveled and was the shore line of the yreat coastal
plain now represented in the Llano Estacado deposits. During this epoch much of
its unconsolidated mass was removed, and reappears as the silt of the Llano Estacado
formation, 'the later Pleistocene erosion has still further degraded the plateau and
reduced its thickness and extent.

Tin-: Llano Estacado.

For those portions of the greal plains proper lying easl of the Raton-Las Vegas
plateau, south of the Cimarron river and east of the Pecos, the term Llano Esta-
cado was appropriately applied by the early Spanish explorers, but the term is now
usually restricted to the portions south of the Canadian. In surface features the

88 PROCEEDINGS OF WASHINGTON MEETING.

northern half of this plain is similar to that of the Tertiary plains of eastern Colo-
rado, Kansas and northward, but it differs from them in that, instead of extending
to the Rocky mountains on the west or imperceptibly grading into the level of the
eastern areas, it is surrounded on every side (except a few miles at the southeastern
corner) by a more or less marked and often precipitous escarpment of erosion which
completely insulates it from all other regions, except the Edwards plateau toward
the southeast, which is its direct coastward continuation and genetically a portion
of it.

Within the past few years the new railroads of Texas and New Mexico have
made accessible to the geologist this greatest of all the plains, and perhaps areally
the largest and least studied plateau of our country. < reographically it includes the
quadrangular region south of the Canadian, east of the Pecos, and west of the one
hundred and first meridian. The scarps which surround it are very irregular and
least conspicuous upon the eastern edge, and are marked by many deep, vertically
incised canons, such as canyon Blanco, winch is nine hundred feel deep. Easterly
projections of these plains extend down the principal drainage divides, ami prob-
ably were once continuous across the present denuded region to the Grand prairie,
as is still the case with the divide of the Pecos and Colorado. The northern and
western escarpment valleys, i.e., those of the Canadian and Pecos,are more precipi-
tous, being over 1,200 feet deep, and receive none of the surface drainage of the
plain, owing to the diverse slope. The surface of this plain is nearly smooth and
unbroken except at its edges, and constitutes as a whole the largest area without
surface drainage in our country. It slopes eastward to the rate of 20 feet per mile,
and its greatest elevation, at the northwestern corner, is 5,500 feet. Hydrograph-
ically the whole surface is void of running streams, and the small amount of surface
water not imbibed by the soil is found in a few widely distributed ponds. Its east-
ern and northern edges are incised by deep, vertical canyons of tributaries of the
Red, Brazos and Colorado systems, which are cutting into it by retrogressive or
headwater erosion. Two streams have cut completely through the plains and into
the Red bed and Cretaceous floor; these are the Canadian and Pecos. But neither
of these receives any of the surface drainage of the plain and both are true moun-
tain streams.

The residual soil of the plain is mostly composed of the transported sedimentary
debris of the Rocky mountains and the Las Vegas plateau. From its structure
and composition it is evident that the soil is a littoral or alluvial deposit laid down
in late Tertiary time. This soil differs from most others in Texas, and, notwith-
standing the deficient rainfall, the plains an> being rapidly settled by an industrial
population.

The geologic structure of the Llano Estacado is as simple and uniform as its
topography, consisting of a surface sheet of unconsolidated porous sediments, com-
posed mostly of water-worn gravel, sand and silt occurring in horizontal layers.
averaging 200 feet in thickness throughout its extent, as ascertained by numerous
well borings and measurements of tin' escarpments, and deposited unconformably
upon the various older rocks which constitute its floor. The greatest thickness of
the formation is toward the northern margin of the plain, and it gradually thins
southeastward.

The peculiar heterogeneous character of the unconsolidated formation has been
well described by Professor Robert Hay as grits, mortar beds and marls. Certain
layers are composed of hard siliceous pebbles, which are recognizable as the debris

It. T. HILL — THE TEXAS-NEW MEXICAN REGION. 89

of well-known Rocky mountain formations. Others consist of coarrse water-worn
quartz sand, loosely cemented by a lime matrix, so that they are literally coarse
mortar beds. The silt is usually pinkish or light chocolate brown, and Conns a rich
agricultural soil when watered. Another typical aspect is known to the Mexicans
as the tierra blanca, or white earth. This occurs as strata of white calcareous chalky
matter possessing strong hydraulic or setting properties, and usually forms the pro-
tecting or cap layers of escarpments. It is composed of sulphate and carbonate of
lime derived from the sediments of chalk and gypsum. The tierra blanca is well
shown north of Toscosa in the bluffs of the Canadian, in the bluffs of the Palo Douro
canyon, and in the railway cuts of the Texas Pacific west of Sweetwater, Nolan
county. The surface sheet extends south of the Texas Pacific an indefinite distance
on the Edwards plateau. It readies the Rio Grande in Val Verde county, north of
Del Rio, and I am inclined to believe that it once covered the whole of the Edwards
plateau, and has since been largely eroded. There are closely related features in the
neighboring coast regions of Texas and in the Rio Grande embayment.

The floor of the Llano Estacado, or that portion underlying the above-described
cap-rock formation and outcropping as the basal portions of its escarpments, is more
complicated hut of great interest in the geologic history of the region, inasmuch
as it represents a great baseleveled land which existed prior to the plains deposi-
tion. Its conditions and structure can best be conceived, however, by considering
the present diversity of formations constituting the earth's surface, sands, clays, etc.,
and imagining a great subsidence which would reduce these to a common haselevel
and spread over the various rocks a sheet of sediments similar to the Llano Estacado
formation and the Lafayette of southeastern United States.

South of the 32d parallel this floor, which becomes the surface by the still Later
denudation of the Llano formation, is composed of the rocks of the Comanche
series, from the Trinity sands to the ( Japrina limestone mostly, the latter formation
constituting by far the greatest area, extending over thousands of square miles in
the counties of Midland, Ector, Tom Green, Pecos, Coke, Glasscock, Crane, Upton,
Irion, .Menard. Crickett, Sutton, Kimble, Edwards, Val Verde, and Kinney. Toward
the northwest this floor was eroded down to the Trinity sands, and even these
were worn away over the greater portion of the vast area previous to the plains
deposition.

Tin' remnantal Trinity sands occur beneath the escarpment of the plains along
the eastern slope of the Pecos valley, at the Headquarters ranch, east of Eddy,
New Mexico, where the limestone and clay beds have completely disappeared.
The sand hills of Texas and New Mexico, at the foot of the western escarpment of
the plains, are probably in large part remnants of the formation. These sand hills
cover hundreds of square miles along the western (or Pecos) escarpmenl of the plains
in various counties of Texas and eastern New Mexico.

Along the northwestern escarpmenl of the plains and along many of the buttes

and mesas of the Red Liver valleys there is another outcrop of what may also he
considered the Trinity sand. There is no evidence of its presence along the entire
northeastern quarter in the canyons of the lied and Canadian rivers. Wherever
this sand is found it indicates the greal degradation which the pre-Llano Esta-
cado deposits have under-one and the important place they occupy in the geologic
history of this country. This degradation 18 worthy of especial attention, for
it was even greater than that which has taken place since the Llano Estacado
deposition. By the Neocene baseleveling an inestimable amount of the Red beds

XII Rum.. Gi "i . 8qi \ M . Vol.. 5. L891 .

00 PROCEEDINGS OF WASHINGTON MEETING.

and the upper and lower Cretaceous sheets, as well as the rocks of the mountains
proper, were degraded and redeposited. Especially is this true of the great rock
sheets of the Comanche series, so fully developed to the eastward, and the absence
of which to the westward in the Rocky mountain region has so long been a subject
of perplexity, They had already suffered much degradation in the haseleveling
which took place during the Dakota epoch, and the degradation of the Llano Esta-
cado epoch still further reduced, almost obliterated, the remainder.

The great canyon of the Canadian lying between the northern escarpment of the
Llano and the southern escarpment of the Raton-Las Vegas plateau averages 40
miles in width, and is 200 miles in length and 1,200 feet in depth. This is an un-
doubted valley of erosion, which has removed 8,000 square miles of the plains and
2,000 cubic miles of the earth. The valley of the Pecos from the mountains to the
Texas line has removed a similar amount. On the eastern margin, over the vast
central denuded region, the erosion is just as plain to a geologist. The eastward-
projecting tongues forming the divides of every stream from the Platte to the Llano
all testify that they are but the rapidly decaying remnants of the greater areas that
have been destroyed, and these divides extend as far east as the 98th meridian.

There is still further evidence of this eastward extension in two interesting areas,
the Edwards plateau and the Washington and Fayette prairies of the east.

'I'm-: Edwards Plateau.

The ( 'olorado river cuts a very deep canyon through the < irand prairie in Travis
and Burnet counties, separating the central or Fort Worth area from the southern
or Edwards plateau. The latter is that portion of the (irand prairie south of the
Colorado and east of the Pecos. Its width from east to west is greater than its
length from north to south, and as it lies mostly within the truly arid region it is
not well adapted to agriculture. Its surface is more uniform than that of the arid
Llano, being composed of hard limestone strata which terminate on all sides by
descending fault escarpments, instead of dipping beneath some newer formation as
do all the rock sheets of the northern divisions of the (irand prairie. This region
has hitherto had no specific name, being usually called " the mountains," from the
escarpments which surround it. It is now proposed to call it the Edwards plateau,
from Edwards county, where it is greatly developed.

This plateau is one of the most extensive and unique topographic features of the
whole region. It consists of a vast rocky plain of hard Comanche limestone,
covered by a scrubby growth of oak, juniper, mesquite, nopal, and sophora (or
false laurel). It is a good grazing country, hut little adapted to agriculture, except
on patches of alluvial soil in the creek bottoms, owing to the intense dryness of
its rocky sub-structure. It, in conjunction with the Llano Estacado, is a typical
plateau of the mesa type, its eastern and southern margins being everywhere
marked by descending or step-oil' escarpments, the result of the great Balcones
fault by which the whole Black prairie region east of it has dropped down from
500 to 1,000 feet.

The downthrow east of this great fault is conspicuous only south of the Colora-
do-Brazos divide, some ten miles north of Austin. From that point southwest-
ward to Del Lio, where it crosses into .Mexico, it becomes more and more con-
spicuous as a great escarpment line, visible to the westward of the International
railway as far south as San Antonio, and from that point westward, north of the

I;. T. HILL — THE TEXAS-NEW MEXICAN REGION. 01

Southern Pacific railway to Del Rio, the directions of the portions mentioned of
both of these roads being controlled entirely by it. To this eastern escarpment of
the Kerrville plateau the Mexicans have applied the appropriate name "Balcones."

The northern border of the Edwards plateau is marked by the southern wall of
the Colorado canyon from Austin to Travis peak as an irregular escarpment of erosion
running westward through San Marcos and McCullough, forming the boundary of
the Llano-Mason Paleozoic area. It turns westward and southwestward through
Concho and southern Tom Green counties, and thence irregularly forms the breaks
of the Concho river ; and it merges with the Llano Estacado in Howard, Martin.
Tom Green and Midland counties. It is a true escarpment of erosion.

An examination of the map will show that the Edwards plateau proper east of
the Pecos occupies many thousand square miles, including most of the counties of
Pecos, Edwards, Crockett, Schleicher, Yal Verde, and Bandera and about one-half
of the counties of Kinney, Uvalde, Bexar, formal. Hays. Concho. Tom Green,
[Hon, Upton and Crane, and a small portion of Travis. In Upton and Midland
counties the rocky surface of the plateau In ■comes the prevalent floor of the peculiar
Llano Estacado formation which extends thence northward. Its narrowest width
is found along the 32d parallel ; after crossing this narrow neck, about fifty miles
in width, the western escarpment is reached, forming the eastern breaks of the
Pecos valley, and continues southward along that stream forming a valley from
500 to i.iiim) feet deep to the Rio Grande. In fact, the Edwards plateau is hut the
southern continuation of the floor of the great Llano Estacado plateau, the same depo-
sition level from which the Llano Estacado formation has been mostly eroded.

The greater part of the summit of the Edwards plateau, like the Llano Estacado,
is void of streams. Its eastern margin is indented by a number of streams, which
are the most beautiful in the state of Texas* These streams usually have enormous
canyons in proportion to their volume. They are mostly mountainous toward their
headwaters, but near the point of emergence from the Balcones escarpment they
How through their own debris in canyons and valleys vastly out of proportion to
their present volume, which no doubt represent the ancient sea level of the Rio
< irande embaynient.

It will he well to observe that there are no sharp topographic or structural bar-
riers between the I'M wards plateau and I he Llano Estacado. ami that any difference
between them is in the surface formation and due to the greater erosion of the
eastern border. Taken together they constitute a single vasl mesa 500 miles long

and 280 miles wide, surrounded on all sides by escarpments, all of which have their
origin in the underground water of this vast mesa. While composed of the same
strata as the northern extension of the < irand prairie, the Kerrville plateau, topo-
graphically and genetically, should be considered a portion of the Llano Estacado.
Another interesting tact of the Edwards plateau is the series of ancient volcanic
necks along its southeastern margin, from Austin to Del Rio, to which I have pre-
viously given the name of Shumard knobs.

The Led, Brazos and Colorado and also the Rio < irande have cut deep into and
in places entirely through the formation of the Grand prairie (the Comanche series
and their valleys present the same atmospheric terracing as the western border. In
places these river valleys assume the a -pert of vertical canyons, as in the ( loloradoi
I'ecosand Rio Grande. The depth of these valleys In-low the level of the plain
increases southwestward from 200 to 700 feet.

The degradation which the northern borders of the Edwards plateau and its

92 PROCEEDINGS OF WASHINGTON MEETING.

continuation, the western margin of the main Grand prairie, have suffered is enor-
mous, for it together with the former westward extent of the upper Cretaceous and
Eocene and the eastward continuation of the Llano Estacadohave been removed in
Neocene time from almost all of the central denuded <>r Paleozoic region of Texas —
a simple and evident fact, yet so large and profound as imt to have been recognized
by local geologists. This denuded material has all entered into the structure of the
Coast and Fayette prairies, the material and vast extent of which alone, if topo-
graphic proof were lacking, would he sufficient to demonstrate the great denudation.
The genesis of this vast plain, the Llano Estacado and Edwards plateau, has long
puzzled me, for 1 have tried to make it harmonize with the lacustral doctrine by
which its northern extension in Nebraska and Dakota has been explained. Tins
lacustral doctrine, as applied to the Laramie and other post-Cretaceous phenomena
of the west, necessitates a hypothetic land harrier between the eastern escarpment
of these plains and the coast in an area now actually occupied hy valleys of ero-
sion, and without any evidence whatever, structurally or otherwise. Thanks to
the investigations and direct suggestion of 'Mr. McGee, I am now inclined to con-
sider it the interior margin of a great littoral sheet of deposits which extend to the
Gulf. Although this hypothesis involves the erosion in post-Tertiary time of
nearly 200,000 square miles of area, it is sustained by three important lines of evi-
dence :

1. The great land stripping at presenl going on in the central region, and the
eastward succession of the scarps of the series of the coastward incline.

2. The deep incision by the older rivers of this coastal plain, the Brazos and the
Colorado having cut 1,000 feet below it.

."!. The actual remnants of the plain over the denuded area, occupyingthe divides
of the drainage.

4. The existence beneath the coastal clays in eastern Texas of a great formation,
tion, which may prove a continuation of the Llano Estacado sheet.

The Washington Praikies.

Immediately westward of the coastal prairies (which it will be remembered are
composed of unconsolidated clays) there is another region, of which the chief
characteristic is a rich, black, sandy soil, derived from the disintegration of a friable
sandstone, composed largely of well rounded and polished grains of quartz cemented
by a white calcareous matrix — a great water-bearing formation which dips beneath
the coast clays and supplies the artesian waters of that region.

These prairies have been mapped out by Dr. R. II. Loughridge, and the underlying
formation has been described by Roemer, Shumard, and Penrose, the latter propos-
ing for it the name of Fayette sands.

These sands have a remarkable resemblance to the deposits constituting the Llano
Estacado formation, and contain also the peculiar opalized wood and fossil hones
and leaves characteristic of that formation, and it is probable that they are the
same or a closely allied terrane which once extended continuously over the entire
region ; and I am also inclined to believe, with Shumard and Roemer. that they are
of Miocene or Pliocene age, rather than Quaternary, as asserted in the Report of
the Texas Survey.

Dr. P>. F. Shumard, in 1861, correlated this formation with the great plains and
announced* " the discovery, in Washington and adjoining counties, of an extensive

*Trans. St. Louis Academy of Science, vol. -i. L868, pp. I la Ml.
t

R. T. Kith — THE TEXAS-NEW MEXICAN REGION. (-)3

development of * "::" '"" Miocene deposits of the Mauvaisse-Terre formation of Ne-
braska [White River and Loup Fork] which have yielded such a wonderful profusion
of extinct mammalians and chelonians. The Texan strata consist of calcareous and
siliceous sandstones, and white, pinkish and grayish siliceous and calcareous marls.
The calcareous beds are almost wholly composed of finely comminuted and water-
worn shells, chiefly derived from the destruction of Cretaceous strata, and in places
abound in fossil hones and plants, usually in a fine slate of preservation. The
hones * * -' consist of genera" closely allied to or identical with Titanotheriam,
Rhinoceros, Equus, and Crocodilus."

If these relations between the Llano Estacado and the Washington prairie be
true, the great difference in level (there is no appreciable difference in dip) must be
explained, and to appreciate this we must first study the large area known as the
Rio Grande embayment.

The Rio Graxde Embayment.

I have previously explained how the climatic features of all the coastal plain
change south of the Colorado or the Guadalupe, and how the great Balcones fault
escarpment becomes more arid and generally different. This region southward in-
cludes the continuation of the coastal prairie, the Washington prairie, the Timber
Belt Eocene, and the Black prairie, and includes all the Rio Grande counties as far
west as Val Verde, embracing all of Maverick, Encinal, Duval, Nueces, Webb,
Dimmit, La Salle, Starr, Zavalla, Frio, Atascoso, Karnes, Goliad, Refugio, San Pa-
tricio, Wilson. Aransas, ( lameron and the southern or eastern portions of Uvalde,
.Medina, Bexar and Guadalupe. The 97th meridian, which is accepted as tin-
western limit of reliable rainfall, intersects the gulf at Aransas Passand is the east-
ern limit of the region: and if reports he true, the lower part of the region. at least,
is certainly one of the arid portions of Texas, a drouth of over eighteen months'
duration having been recently reported from Hidalago within 100 miles of the coast.
The rainfall, however, is much greater toward its interior margin, from Sun An-
tonio to Del Rio, where the drouth has not extended.

This region is in many respects the least studied portion geologically of Texas.
its predominant and topographic feature is its generally low altitude, the contour
or line of equal altitude of 600 feet, which marks its western margin, making a great
deflection westward along the Balcones escarpment and up the Rio Grande to
Eagle Pass, and thence hack toward the coast on the Mexican side, constituting
a great indentation, as if it had been a hay of the gulf covering the region in
comparatively recent time;* and this is, further proved by the great deposits of
Pleistocene gravel and conglomerate marking its interior border and indicating
late deposition of nt least two formations, and which remains in places over much
of the area, though greatly denuded by a still more recent and restricted elevation,

as seen nearer the Rio Grande valley. I am inclined to believe these sedimenta-
tions to he of late Neocene and Pleistocene age ami closely connected with the
Llano Estacado and Basin epochs of the northwest. The oldest and furthest in-
land of t his debris, visible from San Antonio to Uvalde, is only a thin and incon-
spicuous sheet found at the ancient margin of the Edwards plateau.

The fundamental structure underlying these surface sheets in this v*as1 region is
the system of rock sheets from the Eagle Ford i Ren ton i shales (bordering the fault

* This embayment commenced ul the beginning oi the upper < ret iceous oi Dakota < poch. and was
i epeated many times,

94 PROCEEDINGS OF WASHINGTON MEETING.

escarpment from San Antonio t<> Uvalde) on its interior margin to the coastal
prairies and clays at the coast, with slight variations from the same beds seen in
Texas north of the Guadalupe. This includes a great thickness of unconsolidated
beds. Succeeding the chalks and clays which overlie them, there is a great de-
velopment of sand and sandstones in the glauconitic divisions of the upper Cre-
taceous which here is quite different paleontologically (owing to the different con-
ditions of original sedimentation in this Rio Grande embayment) from the Arkan-
sas-New Jersey development. These uppermost Cretaceous beds, for which I have
proposed the name of Eagle 1'ass beds, outcrop from west of Eagle Pass to the
Webb county line along the Rio Grande, and occur all over the embayment as far
southward as the Santa Rosa mountains in Coahuila, constituting its predominant
formation. Succeeding these are various beds of the Eolignitic, Fayette (Neocene)
and coast prairies; the Fayette corresponding at least in part to the Lafayette, and
the coast prairies to the ( olumbia, of Mc< ree.*

This embayment is a structural feature and primarily the product of an otogenic
event associated with the Rocky mountain uplift, which began in the late Cre-
taceous time and reached its culmination after the close of the Mesozoic, and is
distinctly recorded in the conspicuous features of the Balcones fault and the
mountains of northern Mexico. Its further development is a record of subsidence
and elevation from the above-mentioned epoch to the present time, during which
the shore line projected and retracted toward the present coast, with changes of
baselevel, to interpret which will require much study.

This orogenic movement was the faulting and folding of the great floor of hori-
zontal chalky limestones of the Comanche series, which extended as an almost
uniform dip plain (like the present portion between Red and Colorado rivers) from
the Ouachita mountains of Indian Territory to central New Mexico. The move-
ment resulted in the folding, metamorphism and consolidation of the rocks of the
southwestern portion of this plain in Coahuila and trans-Pecos Texas, and pro-
duced lines of weakness which, by the loading down of the Tertiary and Quater-
nary plains, developed into the great Balcones fault, extending at right angles to
the axes of the Coahuila mountain blocks from Del Rio via Uvalde, San Antonio,
Austin and Round Rock, a distance of 200 miles. This fault was fust pointed out
by Professor E. 1'. Cope, and is one of the most conspicuous features of Texas. It
was the downthrow of this fault that constitutes the Texas margin of the Rio
Grande embayment, and along the escarpment line are great deposits of littoral
and estuarine gravel and river terraces, which are the records of the late Tertiary
and Pleistocene baselevels. The summit or plateau west of this fault line has been
already mentioned as the Edwards plateau.

Upon the opposite or Mexican side, beyond the valley of the Rio Grande, an
analogous condition exists, the great difference being that the plateau, which in
Texas extends inward from the interior margin, is there broken up into mountain
blocks and is completely surrounded in some cases by the Pleistocene deposits.

Around the margin of the interior of the embayment there are evidences of
igneous activity, consisting of volcanic necks on the Texas side, the flows from
which, if they ever existed, having been destroyed by post-Tertiary erosion. In
the Sabinas valley of Mexico fragments of the flows are preserved, but show
Pleistocene degradation on every side.

It is my present opinion that the great fault separating the Edwards plateau

*12th Ann. Rep. U. S. Geol. Survey, 1892, i*. 502.

R. T. HILL — THE TEXAS-NEW MEXICAN REGION. 95

from the Rio Grande embayment was accentuated, after having already begun in
late Cretaceous time, by the loading down of the embayment during Pliocene and
Pleistocene time with coastal sediments, thereby breaking the present hysometric
continuity of the ancient Llano Estacado baselevel to the coast.

Basin Deposits of the Trans-Pecos Region.

( 'Intruder of the Basins. — In addition to the vast sheet of Llano Estacado deposits
in Texas, Kansas. Colorado, Nebraska and northern New Mexico, which are sur-
rounded more or less upon every side by descending escarpments of erosion, there
are many large areas of a somewhat similar but newer formation occurring in valleys
eroded in the plains or enclosed by mountain blocks occurring as flats or basins
between the mountains, often many hundred miles in length. These so-called
basins laying between the mountains constitute nearly all of the irrigable and table-
lands of the region west of the Pecos.

The Rio Grande flows most of the way in basins for five hundred miles south of
Albuquerque to a point near the Quitman mountains, except at the mountain passes
at the southern ends of the Mesilla and the Jornado basins respectively. The river
lias cut far into and below the latest level of the basins. Below- El Paso, near Fort
Hancock, the depth of the lacustral deposit cut through is twelve hundred feet, and
the river has almost reached the ancient hard-rock floor.

lite ITueco-Organ Basin. — One of the most extensive and characteristic of these
great inter-mountain basins of post-Tertiary sediments is that lying between the
Organ-Franklin and Hueco-Sacrarnento ranges in extreme western Texas and south-
ern New Mexico. This vast expanse of apparently "deadlevel " plain, extending
from the Rio Grande northward some 150 miles, is from 90 miles in width at its
southern end to 40 at its northern. The Rio Grande cuts through its southern end,
exposing a grand section of the structure from El Paso on its western side to Etholen
station on the east. The basin, although apparently level, slopes southward, accord-
ing to the Whiteoaks railway profile, from 4,500 feet at its northern end to .'1,500 feet
at its southern end.

< )n all sides this flat or basin (locally called " The Mesa '* at El Paso) is surrounded
by high mountain blocks, including the Juarez, Franklin-Organ and San Andres
blocks on the west and the Sierra Blanca, Hueco and Sacramento blocks on the
east, all composed of hard, impervious, metamorphosed limestones, quartzite, gran-
ite, porphyry and basalts, the stratified rocks being of all ayes, from the Silurian to
the < !retaceous.

The soil of the basins resembles that of the Llano Estacado, and is the residuum
of the substructure of loose or unconsolidated sands (grits), " tierra blanca." clays
and water- worn gravel. Around the margin of t he basin near the mountains there
are greal fen-shaped benches of debris from the mountains, distributed by the
torrential streams running down the slopes and covered with sotol and yucca, the
foothill Mora of the region. These marginal deposits constitute extensive terraces
in places and are composed of boulders of mountain rock of all sizes and shapes.

The structure of this basin formation is beautifully shown in the escarpments or
mesas of the Rio Grande valley east of El Paso, where the " tierra blanca," or cal-
careous conglomerate, can be seen capping the scarp, and in the bluffsialong the
railroad bet ween Etholen and Fori Hancock, where the soft, disintegrating escarp-
n lent has every aspeel of the typical " bad land " formations of the arid regions.

96 PROCEEDINGS OF WASHINGTON MEETING.

These beds, like all the post-Tertiary deposits, arc chiefly marked by their noncon-
solidation, the sands, clays and gravel being almost as loose as when first deposited.
White chalky lime strata, or " tierra blanca," resembling the Cretaceous beds, are
numerous; but upon examination they are always found to he conglomeratic and
composed of debris of the "jeso," or decom'posed gypsum of the Red hods, and the
chalky strata of the Cretaceous, mixed with the mountain debris.

These beds were clearly laid down in the mountain troughs or valleys by lake
sedimentation, and are of later age than the Llano Estacado formation. They
never enter into the disturbed mountain structure, but are deposited unconformably
like a matrix around the mountain bases. Their depth or thickness would be dif-
ficult to estimate, hut it varies from nothing at the mountain edge to at least 1,000
feet in thickness in the southern center of the basin.

The northern end of this valley or basin presents several peculiar phenomena,
the principal among which are the celebrated white sand-. These are composed of
rounded grains of gypsum instead of silica, and throughout their extent water is
easily secured by digging a few feet. The northern end has also been covered by a
great flow of lava or "malpais," mentioned later on, which it is alleged flowed down
the valley some thirty miles from the alleged craters in township lit, range 10, first
standard parallel. Although this flat or valley has not upon its surface a single
running stream or even a drainage channel, so that its surface is the most complete
picture of aridity imaginable, yet beneath it lies an illustration of one of the most
important artesian basins in the west. The rainfall in this region is mostly upon
the mountains that surround the basin, standing some 3,000 feet above its plain,
and the water flows rapidly down their sides until it readies the plain. Many of
these streams, like the Rio Tularosa and the Tres Rios, are perennial, and others
all along the mountain range carry great volumes of water during the winter and
autumnal seasons. Immediately upon leaving the impervious mountain rock and
upon reaching the plains these streams disappear completely, a phenomenon which
cannot but impress the observer with wonder and astonishment. They do not
evaporate, as has been alleged, nor do they sink into caverns, as most people think,
but they are imbibed, literally drank up. by the soft, sponge-like formation of the
plain, and are stored below the line of saturation. The shedding of its rain-waters
by the impervious mountain rock and its imbibition by the spongy plains rock is
the key to the whole question of underground waters in the arid region, for not a
single flowing well has ever been obtained west of the tooth meridian and south of
the Dakotas in the consolidated mountain structure.

The Hueco-< >rgan basin is accompanied by many terrace benches around its hol-
der. These are of two kinds: (1) remnants of ancient shore lines; and (2) delta
deposit- of dohri- brought down by present fl 1- upon the mountains. The ter-
races are especially well shown in the pass of the Rio Grande at El Paso, where on
the northern side seven or eight tiers of them above the river level can he traced.

The Mesilla Basin. — -West of the < Irgan-Frankhn range there is another extensive
basin which is occupied by the valley of the Rio < rrande and extends from near old
Fort Selden to Frontera. four miles west of El Paso. Tins basin is hounded on
the west by small mountain blocks running north toward the Fort Selden eruptives.
[n this basin are situated the towns of Mesilla ami Las Cruces, two of the most
flourishing place- in New Mexico, and extensive agriculture is carried on by irriga-
tion from the Rio < rrande.

The formation of this hasin is the same as that of the Hueco-Organ basin, and

R. T. HILL — THE TEXAS-NEW MEXICAN REGION. 97

;il certain stages it was no doubt continuous with that of the latter valley. The river,
which leaves the consolidated mountain ruck at Fort Selden has cut deep into
this plain, and much of its waters are imbibed by the porous formation until it
again enters the mountain rock near El Paso.

The Jornado del Muerto Basin. — The northern end of the Mesilla basin or plain is
terminated by a group of stratified and volcanic hills, which extend westward from
the Organs, via Donna Anna and Fort Selden, cutting off the Mesilla basin from
that of the Jornado del Muerto, which begins north of this barrier and extends
northward for a hundred miles. This is perhaps the most noted of the basin plains,
having been long celebrated for its absolute lack of surface water, and lying directly
in the track of the ancient Santa Fe-El Paso trail.

The Jornado occupies the country north of the Donna Anna hills from Fort Selden
northward. On the east its limits are the San Andres and Sierra ( >scura, the north-
ward continuation of the ( >rgan range. On the west it is bounded by the Sierra de
Los ( "a hallos and Fra Christobal, the southern continuation of the Sandia range.
The Atchison, Topeka and Santa Fe railway enters it at Socorro, and continues upon
it northward to Lava station.

This basin was partially described by Dr. G. G. Shumard* as follows: "Wher-
ever examined the surface formation was found to consist of detritus of rocks
in all respects the same as those composing the neighboring mountains from
which it was doubtless mainly derived. The precise thickness of this deposit
could not be very accurately determined, as only a few natural sections were ob-
served, and these only near the base of the mountains. In two localities its ob-
served thickness was nearly five hundred feet."

The Eagle Flats Basin. — Another and extensive formation lies between the
parallel mountain ranges of the Quitman-Muerto series [which is a continuation of
the Hueco series) and the Diablo-Davis series. This basin is of irregular area and
lias two principal arms or members, the southwestern of which is traversed through-
out its greatest length by the Southern Pacific railroad from Sierra Blanca to Marfa,
and is known as the Eagle flats. This is a very narrow basin, seldom exceeding
twenty-live miles in width, and like the others is surrounded on all sides by moun-
tain blocks, against which may he clearly discerned the terrace structure of the
ancient lake shores. The soil is the same pink-tinted gravelly loam of all the
mountain basins.

From Sierra Blanca this basin sends another arm eastward and northward up the
eastern side of the Hueco series and west of the Carizzo and Diablo mountains
toward the Wind mountains for an unknown distance. In this portion of the basin
there are several salt lakes of small area and extent. The Texas Pacific crosses this
portion of the area, east of Van I hnn, through a mountain gap.

Valley of flu Salt Lake Basin. -Another vast basin extends along the meridian of
HU" from the southern end of the Guadalupe, north of Wildhorse station on the
Texas Pacific. The basin is aboul thirty-live miles from northwest to southeasl and

half as wide, and is marked by numerous salt lakes. It is surrounded on the uv-t

by the mi unit a in b locks of the sierra Diablo, on the north by the Guadalupes, and
on the east and south by low unnamed mountain blocks. From descriptions, this

*'l'li, i, ,i structure ol the "Jornado del Muerto,'" New Mexico, being an abstract from the

ological reporl of tin expedition under Capl John Popi . I — . Top. Engrs., for boring artesian

wells along the Hi f the32d parallel; by Dr. G. G. Shumard, M. D., geologist of th( expedition:

Transactions ol the Academy of Science of St. Louis, vol, i. I85G -'60, p. ■'. n .

XIII Bun,. G koi 3oi \ w \ 891

98 PROCEEDINGS OF WASHINGTON MEETING.

must be one of the most interesting of the great basins, but the writer lias been
unable as yet to visit it.

Basin of Mimbres. — West of the chain of mountain blocks, including the Floridas
and Li is Mimbres-Black range groups on the east, and the Sierra Baca, Pyramid,
Hatchet, Burro and Black ranges on the west, there is another vast basin into which
drains the river known as the Mimbres and numerous othertypical lost rivers, most
of which come from the Mimbres and Black mountains. This basin, with its
southern extension the Florida plains, includes about fifty townships, or 9,000 square
miles, in the United States, and at least as much more in Mexico. Its surface pre-
sents the same level topography and its formation is composed of the same lacustral
debris as in the other basins mentioned, ami like them it has a drainage slope
southward.

The northern end of this valley receives nearly all the mountain waters from the

Black and Mimbres ranges, ami like the Franklin-Hueco basin is characterized by
numerous lost rivers. One of these, Los Mimbres, is the most conspicuous of all the
lost rivers of the west, and has been the cause of much speculation and wonder. It
is a boldly flowing mountain stream until it gets well out upon the plain, when it
completely disappears by imbibition and evaporation.

Probabli Basins oftfa P< cos Valley. — The Rio Pecos, from the mouth of Delaware
creek to Pecos city, fifty miles below, and thence to an undetermined point some
fifty miles further southward, flows in grits and clays of the typical basin character,
which, together with the topographic conformation and well-boring records of the
region, lead to the belief that this portion of the Pecos valley is another < Quaternary
basin. The escarpment of the Llano Estacado is far east of Pecos city, and the river
Hows in a flat or basin some thirty miles wide from Toyah to Quito, which seems
entirely unlike a river floodplain. This flat is marked on the east by a high scarp
line near Quito, 12 miles east of Pecos city, but inasmuch as theapparent shore-line
formations were of the softer Red beds and plains formations, instead of the harder
mountain rock like that of the other basins, it is difficult to say, after my brief
studies, whether or not it is a true shore line, although I am greatly inclined to think
it is. The western shore of this apparent basin is the west of Toyah, against the
eastern slope of the Davis mountains. Both at Pecos city and at Toyah numerous
artesian wells have been found in this alluvial deposit, whether it be of lake or
river origin.

The Volcanic Areas of eastern Xew Mexico.

Besides the older eruptive rocks of the mountain proper, large areas of the plain
and basins of Xew Mexico and Mexico, though not of Texas, are covered by heavy
volcanic flows of lava and basalt hundreds of square miles in extent. In many
eases these are accompanied by cinder c< »nes i »r craters ; others are fissure extrusions ;
and in still others the sources of the flows have not been determined. These lava
sheets are especially conspicuous in the vicinity of many of the ancient basins pre-
viously described, and their proximity suggests that there is a close relation be-
tween therh.

The Raton-Las Vegas plateau was originally capped by a vast sheet of basaltic
lava, which is still the determinative or initial feature in the elusion of the plain of
that vast region, which has been mostly worn away. It still surmounts Fishers
peak, south of Trinidad, and the great Mesa de Maya, extending fifty miles eastward.

11. T. HILL — THE TEXAS-NEW MEXICAN REGION. 99

It also caps the Eagle mountains and vast areas to the southward as- far as Las Mora
creek. The source of this basalt is undetermined, but it is supposed to have flowed
from fissures and not from craters in early Tertiary time. At a lower altitude and
apparently of later age, along the eastern border of this ancient basaltic flow, at its
contact with the Llano Estacado formation, and in the vicinity of Folsom, there is a
group of volcanic craters, composed of cinder cones of from 100 to 2,750 feet in height
above the plain, from which have been extruded vast sheets of lava and basalt,
covering tlie country for miles around and extending more or less irregularly from
Folsom to Rabbit Ear mountains near the Texas line, 100 miles distant and north
and s< iiith of the road about 50 miles, partially covering an area of 1,000 square miles.
The most conspicuous of these craters is Mount Capulin, six miles south of Folsom
station. This, a beautiful cinder cone (altitude, 9,000 feet), rises nearly 2,750 feet
above the railroad, with a vast crater at its top nearly a mile in diameter, slightly
broken down on its western side. From its summit many flows can be tract s< 1 .* To
the southward from six to twenty miles there are several similar craters, while to
the northward there are several smaller ones, called montcules by the Mexicans.
Around these craters there are numerous flows of vesicular, ropy lava.

These are the easternmost known craters of the Rocky mountain region, and
their occurrence at the contact of the Llano Estacado shore line (or depi >sition level)
and the Raton plateau is interesting. The cinder cones are clearly of a more recent
origin than the adjacent basaltic cap of the Raton plateau, for they are situated in
an eroded valley between the main mesa and an outlier — the Sierra Grande — and
at a lower altitude than either of them. They are also apparently more recent
than the late Tertiary deposits of the Llano Estacado, the original surface of the
lava resting upon the latter and not covered by it except in case of the wind-blown
debris.

For two hundred miles southward no more of these craters are encountered until
we reach the head of the Hueco-Organ basin, between the San Andreas and
Guadalupe mountains, on the stage road from Socorro to Fort Stanton. Here
again there is a great area of "malpais" lava, which is a terror to the traveler and
a barrier to the development of the country which it covers. f

The northern end of the floor of the Mesilla basin is covered by another lava
flow, through which the railroad cuts at Fort Seldom Picocho peak and several
others, some ten miles west of Mesilla, are volcanic cones. Of these Dr. G. <i.
Shumardsays: "From the character and general appearance of these cones and
lava streams I am disposed to ascribe their origin to a comparatively recent geo-
logical period. They form part of an extensive volcanic chain, which may be
traced north and south Cur several hundred miles.''

The northern end of the Jornado del Muerto basin also is occupied by a great
lava sheet, 12 by 8 miles in area, or 96 square miles. This, too, is alleged to have
come from a crater, about 10 miles east of t he road, and bears the same intimate
relations to the basin floor as the other crater Hows mentioned.

Another crater How upon the floor of the basin is about 30 miles northwest *<( El
Paso, bet ween A ft en and Aden stations, w here there is an alleged coneof great mag-

*A brief notice of M t Capulin was published b} Ovestes St. John in " Notes on the Geologj ol

Northwestern New Mexico": Bull. U. S. Geol. and Geog. Survey of tho Territories, vol. ii, 1876.
; Since this paper wa9 begun Mr. Ralph S. Tarr has published n brief description of this Bow

i \ ricn ii \ al ist, June, 1891).

100 PROCEEDINGS OF WASHINGTON MEETING.

nitude, from which a narrow stream of lava flows southeastward about 20 miles.
There are other areas in western Xew Mexico of volcanic lava, notably that south
of Grand station, on the Atlantic and Pacific railway.

In Trans-Pecos Texas no craters have been noted, although they may occur in
the mountainous regions. Many old volcanic pipes or necks without lava flows
occur between Austin and Del Kio, but they are of entirely different type and age
from those of Xew Mexico. The relation of those cinder cones and suit-recent flows
to those of northwestern Xew .Mexico and Arizona cannot be stated from personal
observation.

Proceeding south west ward into Mexico they still continue, and in cases exhibit
evidences of activity, increasing southward toward the neck of Mexico where the
present epoch seems to represent but a southern continuation of the volcanic and
lacustral conditions which so recently prevailed over the northern portion of the
basin region.

The fact that these cinder cones and lava flows occur in the floor of the Quater-
nary lake basins is indicative of their recent origin. It is possible that future
investigations will show an intimate connection between the drying up of the
basins and the activity of these volcanoes.

It is also evident from the investigations that eruptive activity lias occurred in
the Texas-Xew Mexican region from Cretaceous to the present time, and at least
three well-defined epochs are at present recognizable which may serve as a guide
to future observations, viz :

1. The Austin-Del Rio system, or Shumard knobs; ancient volcanic necks or
laccolites bordering the Rio Grande embayment, begun in later Cretaceous time.
the lava sheets of which have been obliterated by erosion.

2. The lava flows of the Raton system, which are fissure eruptions of Tertiary
time, and which are only partially removed by erosion.

3. The cinder cones and lava flows of the Capulin system, which are late Pleisto-
cene and which still maintain their original slope and extent.

The most valuable evidence of the recent origin of the craters in addition to their
location in the post-Tertiary valleys is their perfect shape and preservation from
the great erosion from which all of the older and more consolidated features of the
country have suffered greatly. To one acquainted with the active erosion of this
region, by both cloudbursts and wind, the preservation of an unconsolidated and
fragile structure like the Xew Mexican cinder cones is the most convincing evi-
dence of newness.

The foregoing features are presented without any attempt at broad correllation
with the coastal or other regions of the United states, although they present a
tempting field therefor. For the present, however, I prefer to leave this task to
others, boping that the remarkable Tertiary and Pleistocene history will receive
that attention which it deserves.

J. VV. GREGORY — RELATIONS OF ECHINOID FAUNAS.

101

The following paper was then read :

THE RELATIONS OF THE AMERICAN AND EUROPEAN ECHINOID FAUNAS.
i;V J. W. GREGORY, P. G. S., F. Z. S., OF THE BRITISH MUSEUM OP NATURAL HISTORY.

Contents.

Introduction page 10]

The Carboniferous Faunas i<^

Permian-Jurassic Faunas 103

The Cretaei - Faunas L03

Eocene ; 1 rn I 1 Higoeene Faunas 104

The Miocene Faunas 105

The Pliocene Faunas 107

Summary of Conclusions 108

Introduction.

Probably every paleontologist who lives on the western border of the great
galearctic province occasionally chafes against the limitation which the Atlantic
places upon our knowledge of the origin or derivation of successive fossil faunas.
In many case,- researches on the paleontology of central and eastern Europe have
given the desired information as to the origin of a British or western European fauna ;
hut in other cases groups of genera and species appeal- suddenly in a certain zone
and as suddenly disappear. The probabilities in such cases are in favor of the mi-

Errata.

Page 101, line 13 from bottom : for "aquatic "
" 103, " 6 " " " "karstein"

read agnostic.

' 105, " 12
" 107, " 27

" 107, " 18

top,
bottom,

" "twinned

U {{

Asterostoma, n. sp.,"
" " Asterostoma "

Jcarsteni.
tumid.

Archseopreuster abrup-

tus, Greg.
Archseopreuster.

ence in the mid- Atlantic to explain tiie ouiicuiTies oi paieuzouiugicai uiauiumiun m
the old world : but, on the other hand, a school composed mainly of zoologists have
adopted a more aquatic attitude by accepting the theory of the permanence of

oceans and continents, which leaves these difficulties unexplained. Certain
physical arguments have been adduced in support of^his view, hut they do not
seem of any great value, and the whole question seems to turn on zoological, and
especially on paleontological distribution. 11' the Atlantic has been permanently a
deep ocean basin uo such littoral tropical Torn is could have entered Europe from the
Wesi excepl during peri 01 Is when the arctic area enjoyed a temperate climate, and

a theory which postulates a scries of such warm periods would he unsatisfactory
even if there were no1 evidence in some cases againsl the " northwest passage."

The question is one of some importance to workers in mosl departments of paleon-
tology. The phylogenisl w ho accepts the theory of the permanence of oceans and
continents is likely to train the branches of his phylogenetic tree along very differ-
enl lines from those thai would be preferred by one who admitted the possibility

100 PROCEEDINGS OF WASHINGTON MEETING.

nitude, from which a narrow stream of lava flows southeastward about 20 miles.

There are other areas in western New Mexico of volcanic lava, notably that south
of Grand station, on the Atlantic and Pacific railway.

In Trans-Pecos Texas no craters have been noted, although they may occur in
the mountainous regions. Many old volcanic pipes or necks without lava flows
occur between Austin and Del Rio, but they are of entirely different type and age
from those of New Mexico. The relation of those cinder cones and sub-recent tl< >ws
to those of northwestern New Mexico and Arizona cannot be stated from personal
observation.

Proceeding southwest ward into Mexico they still continue, and in cases exhibit
evidences of activity, increasing southward toward the neck of Mexico where the
present epoch seems to represent but a southern continuation of the volcanic and
lacustral conditions which so recently prevailed over the northern portion of the
basin region.

It is also evident from the investigations that eruptive activity has occurred in
the Texas-New Mexican region from Cretaceous to the present time, and at least
three well-defined epochs are at present recognizable which mayserve as a guide
to future observations, viz :

fragile structure like the .New .Mexican cinder cones is the most convincing evi-
dence of newness

The foregoing features are presented without any attempt at broad correllation
with the coastal or other regions of the United States, although they present a
tempting field therefor. For the present, however, 1 prefer to leave this task to
others, hoping that the remarkable Tertiary and Pleistocene history will receive
that attention which it deserve-.

.1. W. GREGORY — RELATIONS OF ECHINOID FAUNAS. 101

The following paper was then read :

THE RELATIONS OF THF AMERICAN AND EUROPEAN ECHINOID FAUNAS.
liV .). W. GREGORY, F. (1. S., F. Z. S., OF THE BRITISH MUSEUM OF NATURAL HISTORY.

( 'ontents.

Introduction page LOI

The Carboniferous Faunas 102

Permian-Jurassic Faunas 103

The Cretaceous Faunas 103

Eocene and < Higocene Faunas I'll

The Miocene Faunas 105

The Pliocene Faunas 107

Summary of Conclusions 108

Introduction.

Probably every paleontologisl who lives on the western border of the great
••alruivtic province occasionally chafes against the limitation which the Atlantic
places upon our knowledge of the origin or derivation of successive fossil faunas.
In many cases researches on the paleontology of central and eastern Europe have
given the desired infbrmati< m as to the < irigin of a British or western European fauna ;
but in other case.- groups of genera and species appear suddenly in a certain zone
and as suddenly disappear. The probabilities in such cases are in favor of the mi-
gration of these forms from some western area. If the species in question possessei I
a great range, either in depth or of latitude, they present no especial difficulty ; if
their bathymetrical distribution was or appears to have been great, they may have
come directly eastward ; if they were spread over a wide area or were boreal forms,
they may have worked their way around the shallow waters of the northern margins
of the Atlantic. But there are cases that cannot be thus easily explained. The
genera in question may be shallow water and tropical forms to which the deep and
cold abysses of the Atlantic would present as insuperable an obstacle as an actual
land harrier. If, as seems most probable, these forms did come from the west, how
did they cross such a barrier, or was it in existence at that time? To solve the
difficulties presented by such cases, many geologists have sought to give a scientific
basis to the legends of the fabled Atlantis, and have called a new world into exist-
ence in the miil-Atlantic to explain the difficulties of paleozoological distribution in
the old world : but, on the other hand, a school composed mainly of zoologists have
adopted a more aquatic attitude by accepting the theory of the permanence of
oceans and continents, which leaves these difficulties unexplained. Certain
physical arguments have been adduced in support of gins view, but they do not
seem of any great value, and the whole question seems to turn on zoological, and
especially on paleontological distribution. If the Atlantic has hem permanently a
deep ocean hasin no such littoral tropical formscould have entered Europe from the
wesl except during periods when the arctic area enjoyed a temperate climate, ami
a theory which postulates a series of such warm periods would he unsatisfactory
even if there were not evidence in some cases against the " northwest passage."

The question is one of- e importance to workers inmosl departments of paleon-

tologj . The phylogenisl « ho accepts the theory of the permanence of oceans and
continents is likely to train the branches of his phylogenetic tree along very differ-
ent lines IV those that would he preferred by one who admitted the possibility

102 PROCEEDINGS OF WASHINGTON MEETING.

of occasional direct intercourse between the southern palearctic and nearctic
faunas. To the geologists and paleontologists who try to trace the origin and
migrations of extinct faunas and their evidence as to the physiography of the past,
the question is also of primary importance.

The evidence that would be most conclusive now, of course, lies buried beneath
the Atlantic, and the paleontologist has to turn to America to see whether he can
trace among its fossils the origin of any of the constituents of the old world faunas,
and, if so, to see if he can discover when they entered the European area and by
what route they traveled.

Any comparison of the European and American faunas that might be made with
this end in view must be conducted with greater care than it would be possible for
any one paleontologist to give to the whole of the evidence. A mere examination
of lists of species is quite inadequate. Hence probably more reliable data can be
gained from the detailed study of one group than from an attempt to handle all
the available evidence; at least, this is all the present writer can attempt. The
echinoidea offer especial advantages: the bathymetrical range of the species is
fairly restricted ; the deep-sea forms are very easily distinguished ; the adults at
least, and in some cases the young, are practically non-migratory ; the echinoids
are mostly tropical or temperate in habitat; they occur in abundance from the
Carboniferous to the present; and, finally, as their classification rests upon the
hard parts, their affinities can be more definitely decided than in the cases of most
other classes. Hence in this paper attention is restricted to the echinoidea. It
must, however, be admitted that conclusions based on one class alone are likely to
be modified when the evidence of all the other groups is worked out. The final
conclusion will probably be the mean of the results given by the independent study
of the different divisions of the animal kingdom.

The Carboniferous Faunas.

Neglecting the problematical Silurian and the rare Devonian echinoidea as Lfiviin:
no adequate data for comparison, it is with th" Carboniferous system that the
species become sufficiently numerous to form definite faunas.

In .Mr. S. A. Miller's useful "Catalogue of North American Paleozoic fos>ils" we
find a fairly long list of Carboniferous echinoidea. Deducting one or two syno-
nyms, the list stands as 41 species and I<> genera, to which must be added several
new species recently described and several undescribed forms that occur in the
American museums. Of this fauna of about 50 species, not one representative
occurs in Europe. It is true that 20 of these belong to the genus ArcJiseocidaris, and
most of them have been based on spines and isolated plates; and that while the
discovery of better material would probably reduce the number of species, it might
at the same time demonstrate the identity of some of them with European forms ;
but at present I feel bound to admit that I have seen no evidence of the existence
of any one Carboniferous echinoid on both sides of the Atlantic. The comparison
of the genera is still more valuable and brings out a great difference between the two
faunas. Of the ten American genera only three occur in Europe, viz, Archseoci-
daris, Palsechinus, and Perischodomus.* The other seven genera are peculiar to

* Eocitlaris may seem an additional genus, but the European species referred to it really belong
to Cldaris. and the name has been abandoned as a synonym. The specimen described by Vanuxe'm
as Eocidaris drydenensis proves to belong to a very different genus. The type is now in the New
York State museum at Albany.

J. W. GREGORY — RELATIONS OF ECHINOID FAUNAS. 103

North America. In the same way three of the six European Carboniferous genera
are peculiar to the Eurasian area. The difference between the two faunas is thus
extremely marked, and clearly shows that there was no close connection between
the echinoids of the two areas. The absence from Europe of the great family of
the Melonitidse is especially striking.

Permian-Jurassic Faunas.

Aftei' the Carboniferous system the next fauna of any special value is in the ( !re-
taceous. The Permian of both continents yields a few species, hut not sufficient
for any definite comparison. The paucity of species in the American Jurassic is
also disappointing, as the European echinoids of this age are so exceptionally well
known. Descriptions of several species by Professor Clark are now passing through
the press and serve to encourage the hope that more may be discovered. As yet,
however, the few species known are not sufficient for comparison with the Euro-
pean faunas.

The Cretaceous Faunas.

The Cretaceous system yields much evidence which has been admirably sum-
marized by Professor W. B. Clark in a " Revision of the Cretaceous echinoidea of
North America," * issued as a preliminary notice to his forthcoming monograph. In
this he enumerates 4.'! species belonging to 19 genera; in addition to this are the 7
species described by M. Cotteau from Mexico, including representatives of two
other genera ; some new species found by Professor Clark ; and a species of Linthia
in the museum of the Boston Natural History Society, which, so far as one can
judge from the brief diagnosis of Linthia tumithiln, appears to be new. There are
also several more species from South America and the West Indies; the former,
however, closely resemble the Mexican species, and the latter are a rather isolated
group and may be neglected.! The Cretaceous echinoids of the mainland of North
America may therefore be estimated at about 55 species, distributed among L>.">
genera. i

If this fauna be examined as a whole it presents a very familiar fades to a Euro-
pean echinologist. Only one genus occurs that is not also found in Europe, while
several species are common European forms; but if we separate them into their
successive faunas we find one interesting point brought out — i.e^that the members
of the earlier faunas agree more closely with the trans-Atlantic species than do
those of the upper beds, such as of the Yellow limestone of New Jersey. This is
especially well shown by the small fauna described by M. Cotteau from Mexico.
This yields six good species, of which three are characteristic of the European
lower Cretaceous (Aptien and Urgonien), viz, Diplopodia malbosi, Salenia presten&is
and I'itfiiiJixiddHssaussurei. The EnaUaster texanus, moreover, is not unlike some
European species, and only the form upon which the late Professor Duncan founded
the genus Lani< Ha is quite distinct. The identification of these species rests on the
authority of M. < 'otteau ; his opinion is of especial weight, as the general impression

♦ Johns Hopkins ITniv. Circ. no. 8C, 1891.

I'I'Im- best known of the South American species is the EnaUaster karstein from Ecuador,
described by M. de Loriol. An examination of the type of Spatangua Columbia Lea, now in the

museum of the Academy of Natural Sciei a in Philadelphia, shows that thej ire identical, and ii

inn -i then fore be known as EnallasU r columbianus < Lea).

(The following i the lis! of those recognized in addition to those mentioned in IV"'
Clark's " Revision : " Stereocidaris, Dlplopodin, Coptonoma, Lanieria and Cardirwter.

104 PROCEEDINGS OF WASHINGTON MEETING.

of his work seems to be that he is inclined to limit specific variation within much
narrower limits than do many workers on the echinoids. In the larger faunas from
the upper Cretaceous, as in that from New Jersey, the whole of the species are pe-
culiar to America, and in most cases the species are quite distinct from their Euro-
pean representatives. The abundance and variety of the species of Cassidulus is the
most striking feature in this upper Cretaceous fauna, and they are all quite distinct
from the European species. Dr. Clark does not admit one species as occurring in
the eastern hemisphere (excluding, of course, those described by M. Cotteau), and.
so far as I have been able to examine the American collections, 1 am inclined to
agree with him except, possibly, in the case of Holaster simplex, Shum. \ II. coman-
chesi, Marc), from the Comanche series of Fort Worth. Texas. There are two good
specimens of this species in the American Museum of Natural History, New York.
These seem to be indistinguishable from the European 77. Ixiris (De Luc), a very
variable species in which several well characterized varieties are recognized.
The same variations seem to occur in the American forms, and one of the two is our
H. Isevis, var. trecensis, the other being II. Ixvis, var. planus. Other species from the
( 'oinanche series are very different from the European ones — e. g., the Goniopygus
zitteli, Clark, and Holectypus planatus, Roemer. The latter is an interesting species,
as its ornamentation rather resembles that of the Jurassic forms. The resurrection
of the fifth genital pore is also noteworthy, as it happens in Europe in some allied
genera of the same age.

Hence in the American Cretaceous echinoidea we find the relations to their
European representatives to indicate that the two faunas were very closely allied
in the lowest Cretaceous, but that in later periods of this age the two faunas devel-
oped on independent lines. The evidence of this system is of especial value, as in
Europe there is practically a complete series of echinoid faunas from the Valangian
to the Danian, and thus the difference between these and the upper American
faunas cannot he ascribed to differences of age. The New Jersey Middle marl
fauna must be not only homotaxial but synchronous with some of the echinoids
between the Gault and the upper ( Ihalk.

Eocene axd^Ougocexe Faunas.

A list of the paleogene echinoids from the United States, copied from existing
literature, would give but a poor idea of the composition of this fauna or of its
afiinities. The whole group is in urgent need of revision, and it certainly does not
seem a sparse one. Thus, the collection of the American Museum of Natural His-
tory includes species of Sarsella, Euspatangus, and Breynella* none of which have
been previously recorded from America. The Smithsonian Institution collections
also add the genera Cidaris and Echinarachnius, and the Academy of Natural Sci-
ences the genus Monostychia.

The most striking feature in the echinoid faunas of these two systems is the pre-
dominance of the group of flat clypeastroidea, belonging to the genera Mortonia,
l'< riarchus, Echinanthus ( Leske non Breynius), Scutella and Echinarachnius, and of the
numerous species of Cassidulus and Pygorhynchus. The great series of spatangoids
found in the European Eocenes are hardly represented. The abundance of the
two last genera mentioned is of interest, as they were common forms in the Ameri-

* The Echinanthus of MM. de Loriol and Cotteau, but not of Alexander Agassiz and other American
authors. See a discussion of this question in a paper, now in the press, by the present writer, on
tin/ Maltese echinoids, in the Trans Roy. Soc. Edinb.

J. W. GREGORY — RELATIONS OF ECHINOID FAUNAS. 105

can Cretaceous. It therefore appears that the gradual differentiation of the echi-
noids of the two areas, which commenced in the Cretaceous, had gone on until the
faunas appear strikingly different.

Until a detailed revision of the American Eocene species lias been undertaken it
is perhaps not advisable to carry the comparison further ; but the following notes
on the synonyms of a few of the species appear necessary in order to tender intel-
ligible the use of some of the above-quoted generic terms. This is especially neces-
sary in the case of the genus Mprtoma and its allies. This genus was founded by
Desor in his "Synopsis des echinides fossiles." The diagnosis was well drawn,
obviously from specimens. The only species given was named M. rogersi, and a
reference given to Dr. Samuel Morton's figure of Scutella rogersi. This was unfor-
tunate, as Morton's species is a true clypeastroid, with twinned margins, and be-
longs to the genus Echinanthus (Leske non Breynius). The species which Desor
actually described was ths Scutella quinquefaria of Say. Desor's mistake has led to
great confusion, and the names are applied very differently in different American
collections. In many cases Mortonia is regarded as synonymous with Periarchus,
but this genus seems worthy of recognition. The type species isS. alius, Conrad, but
I have not been aide to see the type of this species. The common species, S.
pilt us-sinensis, is, however, a good example. The names, therefore, accepted by the
writer for this group are :

Mortonia rogersi, Desor non Morton.

Echinanthus quinquefaria (Say).

Periarchus alius (Conrad).

Another thin, flat form, in which a change of nomenclature seems necessary, is
the Sismondia marginalis, Conrad. The type of this is in the Academy of Natural
Sciences, and with its smaller ally, S. plana, Conrad, must he transferred to Monos-

tychia.

The Miocene Faunas.

The Miocene echinoid fauna of the mainland of America is numerically smaller
than that of the Eocene and < >ligocene, but it gains considerably in size if the "West
Indian species be included. Most of the echinoidea described by Ravenel and
Tuomey from South Carolina, and referred by them to the Pliocene, must also be
referred to the Miocene. < >n the other hand, some species from the western states
usually referred to this system seem to be Pliocene or Pleistocene, and are the com-
mon living species ; thus some of the specimens labelled Scutella striatula, Rem.,
really belong to the living Echinarachnius excentricus. Some of the species referred to
the West Indian Miocene seem also to be of later date, such as the Ehynchopygus
guadaloupenm, Mich., a synonym df R. caribbsearum.

Taking, then, the Miocene echinoid fauna with these additions and restrictions,
we find it to present a remarkable resemblance to the Miocene echinoids of
the Mediterranean basin. Tins resemblance is established (1) by the presence
of several species common to the two faunas — e. </., Cidaris meliterms, ScMzaster
parkinsoni, and Schizaster scellse ; (2) by the fact that other genera are represented
by closely allied apecies, as in the case of the Maltese and Jamaican specie- of
Heteroclypem ; and (3) by the presence in both of genera with a very restricted dis-
tribution— e. !/., Agassizia.

Professor Alexander Agassiz, in his interesting accounl of the origin and affinities
of the long existing Wesl [ndian echinoid fauna, has argued that the fact that so

XIV lii ii. oi'.i, Soi , Am \ "i . 3 t-'ii

106 PROCEEDINGS OF WASHINGTON MEETING.

many of thegenera arc represented by equivalenl species un the two sides of Centra
America is clear proof of the former connection between the waters of the Antillean
and Panamaic regions ; but the resemblance between the echinoidea of these two
provinces seems to be less close than is that between the Mediterranean ami West
Indian Miocene. No one species of echinoid is common to both shores of Central
America, and the representative species are often more distinct than those of the
two Miocene faunas. Hence if Professor Agassiz is justified in his conclusi* >n of the
common origin of the Antillean and Panamaic echinoidea, then so also must the
Antillean and West Indian Miocene faunas have been derived from a common
source. And just as it is considered to prove in the one case a depression of Cen-
tral America which brought the waters of the Pacific and the Caribbean into con-
nection, so in the other case we must assume a period of elevation which produced
a hand of shallow sea across the mid-Atlantic. Whether it he assumed that the
fauna originated in the Mediterranean and migrated to the West Indies, or vice
versa, or whether it developed in some area in the Atlantic now deeply submerged,
this shallow water connection is essential.

But there are two explanations that might be proposed that could not involve
any such complete opposition to the theory of the permanence of the ocean basins.
It might be urged (1) that the common element in the two faunas worked its way
around from the one area to the other along the shallow northern shores of the
Atlantic; or (2) that the connection was established by the free-swimming larval
forms. But we are not without evidence against both of these hypotheses. If we
follow the Echinoid fauna of the Helvetian (middle Miocene) from its typical de-
velopment in Egypt, Malta, Sicily, and Italy toward the north we find at the most
northerly area in Brittany that though a considerable series of echinoids remain,
the group of species and genera which ally the Mediterranean to the West Indian
fauna has completely disappeared. It is just the same in America; the Miocene
of South Carolina has yielded none of the samegroup, which is replaced by species
of Mettita, Encopt . Echinocardium, etc. This fauna has resemblances to the West In-
dian, but it is by an element not typically represented in the Mediterranean. Thus.
on both sides < if the Atlantic the evidence seems fairly conclusive that the migration
did not follow the northern route. But we are fortunately not compelled to rely
on negative evidence alone. In the Azores, in Madeira, and in the Grand Canary
there are Miocene beds which have yielded a small echinoid fauna ; in each case
the species when determinable are found to be those characteristic of or close allies
to the Mediterranean Miocene; in some cases the species are represented by the
same varieties. This is, of course, proof only of the original extension of the Med-
iterranean fauna as far west asthe Azores, but this is a very considerable step across
the Atlantic; and some West Indian forms, as Temnechinus, occur elsewhere only at
the Azores, and thus serve to show the completion of the bridge.

In regard to the second hypothesis explaining the connection by the free-swim-
ming larva:' it may be objected that the chances of so delicate an organism as a
pluteus surviving the journey across the Atlantic must be somewhat remote, and
the species would have no chance of establishing itself unless a number of the
plutei arrived simultaneously at a suitable locality. I do not remember that the
Challenger surface nets ever collected any plutei of a littoral species in mid-ocean.
But here again we are fortunately not left to decide on mere probabilities such as
these. Many living echinoidea are now known to be viviparous and to have no
free-swimming stage. Now- Schizaster parkinsoni has in a very marked degreeall the

.1. W. GREGORY — RELATIONS OF ECHINOID FAUNAS. 107

characters of a viviparous form, while Schizastt r scella was probably the same. The
occurrence therefore of these species in both the Mediterranean and Antillean
faunas is quite sufficient of itself to demonstrate the inadequacy of any explanation
based on the passage of the pluteal forms ; some of the forms that crossed the At-
lantic had an abbreviated development without any pluteal stage.

The Pliocene Faunas.

In the Pliocene period the echinoidea are scarcer and less well known than in
the Miocene, and now that most of the species described by Ravenel ami Tuomey
have been transferred to the earlier division no very definite fauna is left. In fact
on the mainland there are only a few recent species, such as Mellita sexforis from
Carolina and Echinarachnius excentrieas (syn. Scutella striatula, Rem. non Marc.de
Series) from the Pacific slope. The collections of the Academy of Natural Sciences
of Philadelphia an i the Smithsonian Institution also contain some specimens of
the living Echinanthus reticulatus, Linn. sp. (sensu Loven; the Echinanthus — or
( 'lypeaster — rosaceus, A net.) from Coloosahatchie, Florida. These, however, seem to
be all recent species, whereas in the European Pliocene but few living species are
represented. The few echinoids from beds of this age in the United States have no
particular afiinities with the European ones.

There are, however, two species of echinoidea from deposits in the West Indies
that may be referable to this age, and which cannot be overlooked, as they have
important bearing on questions of physical geography. They are ( 'ystechinus crassm,
Greg., ami Asterostoma, n. sp., both from the Radiolarian marls of Barbados. The
geological bearing of the discovery of such a typically deep-sea genus as Cystechinus
was referred to at the time of its description, but it has gained considerably in in-
terest by the recent wrork of Profess. >r Agassiz. At the time of the discovery of the
Barbados specimen the genus was only known from the Antarctic and the China
sea. It has now, however, been dredged by Professor Agassiz in deep water off the
western coast of Central America, but the species is so far known only by the few
remarks made about it by Professor Agassiz in his preliminary report on the results
of the cruise ; yet as far as we can judge from these it is cl< isely allied. The species
of Asterostoma is of interest from the Light it throws on the age of the beds in Cuba,
from which the original specimens of this genus were derived, from their resem-
blance to Echinocorys (Ananchytes). M. Cotteau referred them to the Cretaceous,
but the discovery of this Barbadian specimen renders it highly probable that they
should be transferred to the upper Cenozoic.

The paucity of American Pliocene echinoidea is to be regretted, as those of this
age in Europe have been in most cases carefully collected and monographed. With
the few Pliocene echinoids from America they have nothing in common; but as
the writer has pointed out in a recent "Revision of the British fossil Cenozoic
echinoidea," those of the English Crag have many affinities with the existing
fauna of the West Indies. The Crag echinoids number 22 species, and may be
divided into two groups : (1) the common northern European forms, or species
closely allied to these ; and (2) a group of genera represented together elsewhere
only in the West Indian area. Thus, in the English Crag there are species of
Tniiiirchiiiiis, Agassizia, Rhynchopygus, and Echinolampas, of which the nearest
allies are Caribbean species. Now, these are all either tropical or littoral forms,
and it is of interest to note that they do not occur elsewhere among the European
Pliocene deposits. The fauna which agrees besl with that of the English Crag

108 PROCEEDINGS OF WASHINGTON MEETING.

(excluding tl 10 few patches of Pliocene sand in northern France) is that of Bel-
gium. This, however, contains but two British species, though as a rule the species
are allied; the main difference consists in the presence of some Mediterranean
species and the absence of the four genera of the western group. The richest of
the Belgian beds is the Diestian, which is older than our Coralline Crag. This,
therefore, suggests that the "western group," as we may call the second element
in the Crag fauna, did not reach Europe until post-Diestian times, and thus did
not penetrate so far east as Belgium.

In this case the same suggestions as to the possible northern migration or the
floating across of the larvae might be made, and there is Less evidence on the sub-
ject than in the Miocene. The only well-known species of Temnechinus from the
Crag (7". woodi, Ag.) was probably viviparous, and it may be that the West Indian
species is so also; otherwise there is no evidence to directly disprove this second
hypothesis. As there is no known European Pliocene fauna north of the Crag,
and as the Pliocene series from the American mainland is also very scanty, there
is no such means of disproving the northern extension of these tropical or sub-
tropical forms ; hut had this happened we might have expected a much greater
mingling of the faunas of different zones of latitude than has happened. The
echinoidea of the European shore agree more closely with those of the correspond-
ing isotherms on the American side than with the faunas north and south of
them. The presence of Temnechinus maculatus at the Azores as well as in the
West Indies also further suggests that the connection was established somewhere
in the mid-Atlantic.

Summary of Conclusions.

A brief comparison of the successive echinoid faunas of Europe ami America
has thus been attempted, and it may he advisable briefly to summarize the con-
clusions arrived at.

In the Carboniferous period there was an almost complete difference between
the two faunas, whereas in the succeeding Urgonien and Aptien the two faunas
are almost identical. But the Cretaceous period was marked by a gradual differ-
entiation; species ceased to lie common to the two areas, and the representative
forms became more distinct. In the Eocene and Oligocene the same independent
evolution seems to have gone on; the American fauna was rich in species of Cas-
s'ltlulux and Pygorhynchus, genera also common in the Cretaceous beds of the same
continent, and the faunas were more distinct than were the Cretaceous. During the
Miocene there was again a change: afresh connection was established that enabled
the echinoidea of corresponding latitudes in the new and the old worlds to com-
mingle ; and later still, in the Pliocene, there is evidence to show the introduction
into the European area of some American echinoids. The possibilities of this con-
nection across the Atlantic by free-swimming larvae or by the adults having worked
around the northern margin have been examined and evidence adduced against
them, and one case i> quoted in which the dissimilarities of fauna cannot be ex-
plained as due to difference of age.

It is therefore urged that the comparison of the succession of the echinoid faunas
of Europe and America present a series of phenomena wholly incompatible with
the theory of tin' permanence of the great ocean basins.

Remarks were made upon the topic of the paper by Mr. L. C. Johnson.

ARTHUR WINSLOW — THE MISSOURI COAL MEASURES.

109

The next paper was on —

THE MISSOURI COAL MEASURES AND THE CONDITIONS OF THEIR DEPOSITION.

BY ARTHUB WINSLOW.

lAbstract.1
Tin- Distribution of the Carboniferous Rocks page 109

109

11-'

112

113

114

The Ozark Uplift

Age of the Upheaval

The Phenomena of the Coal Measures

Distribution and Hypsometry...

Lithology and Stratigraphy

The Conditions of Deposition

The Distribution of the Carbonifebous Rocks.
The Ozark Uplift.

The Carboniferous rocks of Missouri Hank the northern ami western sides of that
great quaquaversal arch which has been so appropriately termed by Broadhead

Fioi i.i ""/' "i Sfi

110 PROCEEDINGS OF WASHINGTON MEETING.

the Ozark uplift.* This dome-like protrusion is exhibited over an area of not
less than 15,000 square miles in the central portion of the state, south of the Mis-
souri river. Its location is represented in a general way on the small map form-
ing figure 25 by the broad white space west of the Iron [Mountain railway. It in-
cludes topographically the most elevated portion of the state, the plateau mass
called the Ozark mountains being within its bounds. The geological formations
represented are chiefly the Lower Silurian ; these occupying the whole central area
as massive sheets of magnesian limestone, with intercalated sandstones. Near the
center they lie generally in a nearly horizontal position, but toward the margin
of the uplift they slope off radially under the overlying formations.

Age of the Upheaval.

This upheaval was, apparently, thought by Broadhead t to have begun just before
the close of the earlier ( larboniferous, and to have continued until after this period.
The evidence of this would seem, however, far from conclusive. It consists in the
existence of outlying patches of lower Carboniferous rocks within the area of the
uplift and beyond the margin of the main body of the formation. These outliers
are not abundant, ami the most remote mentioned by Broadhead is an occurrence
of Chouteau rocks in Wright county, not over thirty miles from the margin of the
lower Carboniferous area- During the past field season discoveries of lower Car-
boniferous fossils farther in the interior have been made by Mr. .1. I>. Robertson,
assistant of the Missouri geological survey. They were found a few miles southeast
of Rolla, in Phelps county, and also near the northeastern corner of Douglas county.
The fossils were in a few loose fragments of chert scattered over the surface; no
rock being found in situ carrying such organic remains. These occurrences would
seem to indicate the former presence of the earlier Carboniferous sea over these
localities, or the submergence of the area, at that time. On the other hand, how-
ever, the scarcity of these Carboniferous rocks and the total absence of rocks
intervening between these and the Lower Silurian beds, within the main area of
the uplift, goes, so far as negative evidence can go, to prove that the intervening
beds were never deposited entirely over it; that the lower Carboniferous beds
reached up on its sides perhaps no farther than the limits of the outliers referred
to would indicate ; and that these latter, over the < >zark area, were of very limited
thickness, such as were subsequently readily removed by erosion. The last condi-
tion is in harmony with the hypothesis that these lower Carboniferous beds of the
( >zark region were deposited during the earlier part of that period, and that their
accumulation was arrested by the emergence of the area during early Carboniferous
time while the upper beds were still in process of formation in surrounding zones.

( )f movement and extensive uprising after the deposition of the lower Carbonifer-
ous rocks we have abundant evidence. This is shown by the unconformity which
exists between the lower Carboniferous limestones and the overlying Coal Measure
rocks. This unconformity has been so often described by Swallow,; Shumard,^
Broadhead, || White,*! an'1 others as to call for no special demonstration or reference

*The Geological History of the Ozark Uplift, by G. C. Broadhead: American Geologist, vol. vii.
1889, pp. 6-13.
I- Op. eit.,p.l2.

J Report Mo. Geol. Survey, 1855.
Report Mo. Geol. Survey, 1871.
(Report Mo. Geol. Survey, 1873 and L874.
Tj Report Iowa Geol. Survey, 1867.

ARTHUR WINSLOW — THE MISSOURI COAT, MEASURES. Ill

here. It is exhibited, in brief, by tilted lower ( iarboniferous strata, in places under-
overlying horizontal Coal Measure beds, and also by easily recognized pre-Coal
Measure erosion. The latter is shown by the existence of Coal Measure rocks
deposited in these previously eroded valleys, and also by extensive accumulations
of the detritus of the lower Carboniferous rocks in such depressions; these phe-
nomena being frequently observable over the marginal area of the Coal Measures.
Just how extensive this Carboniferous elevation was cannot exactly he stated at
present. There is evidence that, in places, for some fifty miles in from the margin of
the Coal Measures the lower Carboniferous rocks were brought to the surface and
eroded, and it is probable that this extended much farther. It is possible that the
lower Carboniferous floor underlying the whole Coal Measure area of Missouri was
raised above water level and subjected to erosion. However this may be, we are
safe in stating that the Coal Measures were laid down upon an uneven surface, which,
at least over the marginal portion, was decidedly rough, broken by hills and ravines
as a result of erosion. The probable general condition is represented in the accom-
panying figure 26.

^g^r^E^Sl

Figure 20 — Ideal Section through the Ozark Uplift
Representing the probable condition of Hit- floor upon which the Coal Measures were laid down.

Of still farther movement and renewed submergence before the Coal Measure
period, the presence of the Coal Measure rocks upon the uptilted lower Carbonifer-
ous strata, or in the channels eroded in the latter, yields ample proof. Just what
the extent of this submergence was and what were consequently the original limits
of the Coal Measures is another question. Of their original extension over the
Ozark area we have little or no evidence, other than the fact that the thickness of
the Coal Measures in the northwestern part of the state is very great, such that if
the upper rocks there once extended to the present eastern limits of that fi »rmatii >n.
they must have reached far beyond these limits and probably over the < )zark region.
That the upper Coal Measure rocks may never have extended to the present eastern
limits is, however, shown in the following pages ; therefore the former submergence
of the Ozarks is not necessary in order to explain the great thickness of the Coal
Measure strata.

In support of the idea that the present marginal limits are near the original ones,
we have, on the other hand, the fact that tin' present marginal beds are distinctively
marginal deposits, and further, we have the negative evidence that no Coal Measure
strata, which maybe strictly classed as outliers, occur faraway from the general
margin of the formation, well within the Ozark area.*

* In apparent negation of this statement, recent examinations, by the state geological survey, have
shown the presence of those peculiar deposits ol coal known as "coal pockets" in the \ ery heart of

the Ozark region, in Douglas, Dent, Phelps, ami Crawford counties. These, 1 1 . >w .• \ . • c, bj i i<

call for an original extension of the whole formation i" the extent of including them. It i- true

that they are probably of Coal Measure age, bui On- i satisfactory theory of their formation is

that they were accumulated in inland basins, or cavities, for I by previous erosion or solution of

limestone, and were not connected with the main body of the Coal Mi isures. The I they

are frequently found in and Burrounded by Lower Silurian rocks goes far toward proi ing thai the
later intervening rocks were either never deposited where such coal pockets are found or, if de-
posited, thai they were uplifted and entirely eroded before the deposition ol th< i H lire strata
began.

112 PROCEEDINGS OF WASHINGTON MEETING.

Summarizing, therefore, we arc inclined to maintain the view that the move-
ments which originated this uplift were in Silurian times, even Lower Silurian, and
were consequent upon the deposition of the greal mass of Lower Silurian strata in
the sea surrounding the Archean archipelago. Further, the absence, in places, of
Upper Silurian and of Devonian beds under the lower Carboniferous strata, which
lap upon the sides of this Lower Silurian dome, shows that this early and first up-
heaval was extensive, and that large areas were lifted at that time above water
level to be submerged later in the Carboniferous seas for the deposition of the
lower Carboniferous limestone, the limits of which are outlined on the map form-
ing figure 25.* The pre-Carboniferous submergence was sufficient to allow the
waters to reach well up over the sides of the Ozark area and possibly great enough
to place it entirely beneath water level. Uplifting began again, however, soon
after this; so that, at most, only a thin deposit of lower Carboniferous rocks was
formed over the Ozark dome, which was subsequently entirely eroded. This up-
rising continued, perhaps intermittently, until after the end of the earlier Carbonif-
erous period, when the rocks of that formation were brought above the waters and
were subjected to extensive subaerial erosion. At or near the beginning of the
Coal Measure period, submergence began again and continued until, and probably
beyond, the close of that period. The Ozark area remained above the waters
during this submergence, however, and has continued so ever since ; the present
eastern limits of the Coal Measures being approximately the same as originally
outlined.

The Phenomena of the Coal Measures.
Distribution and Hypsometry.

The Coal Measures of Missouri cover the western and northwestern portion of the
state, occupying an area of some 23,000 square miles.t The general outline is familiar
to many, but, for purposes of ready reference, it is given on the small sketch map
forming figure 25. The altitude of the surface within this area varies from about
000 feet to nearly 1,300 feet. Along the marginal lines of the Coal Measures,
from northeast to southwest, the following are the approximate altitudes at succes-
sive points on the summits between drainage channels: Kirksville, 975 ; Macon,
886 ; Mexico, 798 ; Moberly, 807 ; Fayette, 800 ; Boonville, 750 ; Sedalia, 007 ; Clinton,
807; Nevada, 870; Joplin, 1,018.

In the interior, along the western border of the state, the following are the alti-
tudes at successive points located similarly topographically : Kansas ( 'ity, about 050 ;
Leavenworth, about 1,000; Plattsburg, 1,000 ; St. Joseph, about 1,050; Savannah,
1,100; Oregon, 1,100; Maryville, 1,200; Watson, 1,100.

Along the margin the Coal Measures may be considered to thin to a feather edge,
while in the extreme northwestern corner of the state they have an aggregate thick-
ness of perhaps 2,000 feet, and consist of probably more than 200 strata.

*In a paper entitled "The Missouri River." published in American Geologist, September, 1889,
Professor Broadhead states, on page 154, that the < >zark plateau " began to rise just after the < 'ana.
dian. . . . From the Canadian to the beginning of the lower Carboniferous it was dry land. It
then became sufficiently depressed to receive limestone deposits near its outer margin during the
early Subearboniferous, a few l>e<ls of the later Chouteau, and early Burlington." These state-
ments lead one to the conclusion that he lias abandoned the belief of the Carboniferous age of the
uplift referred to on page im, and that the writer's opinions, so far expressed, are substantially in
accordance with those held by Professor Broadhead.

f Report Mo. Geol. Survey, 1872, pari ii. p. 5. .

ARTHUR WINSLOW — THE MISSOURI COAL MEASURES. 113

( >n the basis of the figures above given we'have an elevation of about 900 feet for
the floor of the Coal Measures at the margin near Sedalia, and in the extreme north-
wesl the position of the floor is about 700 feet below sea level. Consequently the
present slope of this floor is 1,600 feet in a distance of some 150 miles, which is equiva-
lent to about 10 feet per mile, or about one-tenth of one degree of slope, which is
almost horizontal. The elevation of the surface of Maryvilleis about L,200 feet :
so that the thickness of the Coal .Measure rocks there found abovethe level of Sedalia
is only about 300 feet; thus the regional elevation which finally lifted the Coal
Measures above the water level was not necessarily much greater in the interior
than along the margin.

Lithology and Stratigraphy.

The rocks of the ( !oal Measures consist almost wholly of sandstones, shales, lime-
stones, and coals.

The sandstones are of white, drab, yellow and reddish colors, are generally line
grained and friable, and are often filled with specks of carbon and with impres-
sions of leaves and stems, especially along the stratification plains ; mica is almost
always present. The sandstones are most abundant and prominent in the eastern
and marginal area of the Coal Measures, and they there constitute a considerable
portion of the section. In the interior or central area they are not prominent
members, though arenaceous shale is abundant, and it is frequently difficult to say
whether such material should properly be classed as a shale or as a sandstone.

The shales are argillaceous, bituminous, arenaceous, or calcareous, and frequently
grade by almost imperceptible degrees into sandstones or limestones; they are id'
black, drab, gray and red colors. The shales preponderate by tar over either of
the other classes of rock, are widely distributed, and are about equally prominent
in all sections of the ( 'oal Measures.

The limestones are sometimes in massive beds, three ami even more feet in
thickness, are occasionally concretionary and in nodular forms, are sometimes
laminated with uneven bedding planes, but are almost always of a fine compact
texture ; they are of drab color, ami are readily distinguished from the white, coarse-
grained, semi-crystalline limestone of the lower Carboniferous. The limestones
are least abundant over the extreme marginal area, and become more frequenl ami
thicker toward the interior ; in the northwestern portion of the state they occur
in beds aggregating twenty or more feel in thickness. Lime is here very abun-
dantly represented in all the rocks; many of the shales, even the black bituminous
layers, being decidedly calcareous. As with t he shales and sandstones, SO with the
shales and limestones, it is often impossible to class a rock positively as a lime-
stone or as a shale.

The coals are all bituminous, with the exception of certain local deposits which
approach cannel coal. The beds range in thickness from one inch to about five feet.
They a:.- generally soft ami pyritiferous, with selenite almost alwaj s presenl in thin
scales along the joint planes. They are almosl in\ ariably underlain bj clay, which
sometimes contains stigmaria casts. They are generally immediatelj overlain by
black shales, frequently fissile, or by a gray or drab claj -hale. In this -hale leaf
impressions are found in places, but the localities are few where such are abun-
dant. Sometimes sandstone rests directlj upon the coal, or a limestone cap-rook
is hareh separated from it by a few inches of claj or -hale, but such instances are

exceptional. The cnal beds are mosl abundant and are thicke-t over the marginal

\ \ Bi i -.■■ \ i Vol ::. 1891

114 PROCEEDINGS OF WASHINGTON MEETING.

portion of the Coal Measures, where they occur near the surface and where they
have heen principally and most extensively operated up to the present time. They
seem here, however, to be mure irregular in character and distribution than in the
interior, so far as one can judge from the limited developments which have been
made in the deep-seated coals of the interim- region.

Among the most noticeable features of the stratigraphy of these Coal Measures
is the variability of details. The strata are characteristically non-persistent, as
regards thickness as well as material. Beds of coal thin out and disappear; beds
of shale pass into sandstone or grade into limestone, as the case may be ; limestone
beds fluctuate greatly in thickness, or may be present or absent in not widely sep-
arated localities. These conditions are particularly prevalent over the marginal
area, among what has been considered the lower Coal Measure rocks. Swallow,*
Norwood,! and Broadhead J all refer to such variations of sections, and they are
encountered in mining operations, often to an embarrassing extent. Of most con-
spicuously irregular distribution are the sandstones of the marginal area. These
sandstones may lie divided into two classes: First, there are the regularly inter-
stratified beds, ranging from two to ten or more feet in thickness, which, though
less persistent than the other beds, can yet be recognized clearly as interstratified
members over considerable areas. Second, there are the great massive deposits of
sandstone, sometimes exposed to a thickness of 50 or 60 feet without displaying
any bedding planes. These may be connected with the thinner interstratified
beds, but where they attain their characteristic development they cannot be
classed as interstratified beds of the Coal Measures, but apparently are deposits
tilling channels which were eroded in the Coal Measure strata presumably during
the Coal Measure period.;;

The fauna of the Coal Measure rocks indicates the previous existence over the
marginal area, in what have been termed the lower Coal Measures rocks, of brackish
and shallow waters, while in the interior, among the rocks designated upper Coal
Measures, marine forms are more abundant. There is nothing at all pronounced
in the fauna which would call for great priority of deposition of the rocks of the
marginal area over those of the interior.

l&*

The Conditions of Deposition.

From a consideration of the facts and conclusions presented in the preceding
pages, it appears that the following conditions must be satisfied by any interpreta-
tion of the process of deposition which may be offered :

1. That the marginal conditions were generally those of brackish water and
favorable for the formation of the coal beds.

2. That marine and deep-water conditions were more frequent over the central
area, permitting the deposition of thick beds of limestone.

* Report Mo. Geol. Sur., 1855, p. 87.

f Report Mo. Geol. Sur., 1873-74, pp. 200-215.

1 Report Mo. Geol. Sur., 1872, part ii, p. 166, and elsewhere.

gThese channel deposits are. in places, a mile or more wide and apparently 200 or more feet
thick; they limit sharply the coal beds and the other regularly deposited strata. Their distribu-
tion is being carefully studied by the state geological survey, and they promise to prove a most
valuable and interesting subject of study. Their exact age is not at present determined, and it is
possible that they may ultimately be assigned to tie- Permian or even to a later period < m the
other hand, if they ••an he traced beyond the limits of the Coal Measiires.it i> probable that at
[east a part of the sandstone which has been classed as the Ferruginous sandstone of pre-Coal
Measure age really belongs to this formation.

ARTHUR WINSLOW — THE MISSOURI COAL MEASURES.

115

.'!. That during the process of deposition the strata from the base to the top of
tin- ( loal Measures were, at intervals, at or near the surface of the water, permitting
the growth of the coal flora and the accumulation of coal.

4. That at least some of the strata were deposited in an exactly horizontal
position.

5. That the margin of the Coal Measures never extended much beyond the
limits at present recognized, and that the strata of the interior never reached over
those of the margin.

According to views hitherto presented, the Coal Measures of Missouri have Ween
separated into upper, middle, and lower divisions, respectively 1,317, 324, and 250
feet thick * all having a slight dip a little north of west. The prevalent opinion
concerning these divisions, as well as those of the contiguous Iowa Coal Meas-
ures, is that they underlie each other successively, and that, should the strata of
the upper Coal Measures in the northwestern part of the state be penetrated by a
shaft, the members of the middle and lower Coal Measures would be successively
encountered. The reservation is generally made, however, that some of the beds
will probably. thin out, disappear, or he replaced by others, so that exactly the same
succession of strata cannot be expected, though whatever, may he included under
the indefinitely applied term " formation " is considered to be continuous. The
adjoining figure 27 represents in a general way the implied and commonly conceived
positions and relations of these divisions of the Coal Measures.

Fioube :!" — Ideal Section of the Coal Measures of Missouri and Iowa.

The nature of some of the Coal Measure strata demands horizontality of position
a1 time of deposition, and as, according to the above representation, the strata are
parallel with each other, they must, on this interpretation, all have been deposited
as horizontal layers and subsequently tilted simultaneously into the present posi-
tion. Further, the existence of coal beds near the base of this formation shows that
even the lowermost strata were accumulated near the surface, and hence, to produce
the conditions generally pictured, would require a regional subsidence of aboul 2.000
feet, equal in rate and amount over the whole area, with which the process of deposi-
tion kept pace equally and exactly overevery portion. A restoration to a horizontal
position of these strata is represented in figure 28, ami it is there apparent at a glance
that, following out this supposition, the portions of at least the upper part of the
formation represented could be only small remnants of the whole, and that, with
the indicated thicknesses, they must once have spread over the whole ( >zark region,
as well as over the area of lower rocks in northern h>\va. We cannot believe such
extension possible withoul at least some remnant of these rocks being left over
territory where t hey are now never found, as already stated in connection with the

* Report Mo, Geol. Survey, 1872, pari ii, p 6.

116

PROCEEDINGS OF WASHINGTON MEETING.

discussion of the age and history of the Ozark uplift. The hypothesis is contrary
to the authoritative and generally accepted views concerning the original limits of
the Coal Measures both in Missouri and Iowa, Such representation of the relation
and positions of the Coal Measure strata leading to conclusions contrary to accepted
views, it behooves us to attempt a presentation of the results and of the process of

Figure 28 — Ideal Section of the Coal Measures of Missouri and Iou-a restored to horizontal Attitude.

deposition which will be in harmony with the observed facts and well substan-
tiated conclusions.

Starting with the indisputable fact, as proved by deep drilling and shafting in the
western portion of the state, that at or very near the base of the ( !oal Measures there
are strata of shallow- water origin, we must allow that the lower part of the floor was
at the beginning of deposition near the surface. We will assume next that sub-
mergence soon began over the central area of the ( !< >al Measures, and that, as repre-
sented in figure 29, the margin of the early Coal Measures sea or swamp />' was well

Figure 2'.i — Idnd Representation of the Beginning of Cod Measun Deposits

within the present limits .1 of the deposits. As soon as this area became submerged
deposition over it would begin ; but, as all material is derived from or beyond the
margin, the accumulation during any stated period would be thickest along the
margin and would thin thence gradually toward the interior, the character of the
material changing at the same time. The marginal area would thus be the first to
become a shallow-water area suitable for the formation and accumulation of coal.
As the basin became gradually filled with sediment from the margin toward the
interior the coal swamp would slowly creep out horizontally, until it covered the
whole surface in a continuous sheet, apparently slightly unconformable with the

ARTHUR WINSLOW — THE MISSOURI COAL MEASURES.

117

underlying strata which were accumulated in slightly inclined positions. Figure 30
represents the resulting conditions, provided deposition is continued and subsidence
is arrested. The number of deposits cannot be taken to represent, strictly speaking,
so many individual and separated strata, as each one may be made up of a varying
number of layers of different materials; they simply indicate the limits reached
by the deposits in successive intervals of time. The apparent dip and the conse-
quent unconformity of the coal layer C C upon these underlying strata is also much

Figure 30 — Ideal Representation of a complete Cycle of Deposition of Coal Measures, and of their

Mode of Accumulation.

exaggerated by the excessive vertical scale. If reduced to the natural scale, neither
the dip nor the unconformity at any one point would be perceptible.

The natural results of such a growth of sediment is that a coal bed should he
thicker near the margin, where its accumulation began, than in the interior, and the
thickness of the bed at any one point will depend upon the length of time during
which subsidence was arrested and the accumulation was allowed to go on. The
coal bed may expand over the whole area, as is represented in figure 30, and may
there accumulate through a thickness of several feet, and then be cut short by a
suhmergence to the point C, when another cycle of deposition will begin similar to
the first.

Changes in the amount and character of the sediment supplied at any time dur-
ing such a cycle would cause corresponding changes in the thickness and character
of the strata. A rapid, continuous, or frequently recurring subsidence would pre-
vent the accumulation of coal, or would allow of its formation only over narrow
marginal areas. A subsidence after the coal bed had expanded overa half or other
fraction of the submerged area would fix a limit to that individual bed at such point,
and it would be buried beneath the strata of the succeeding cycle of deposition. A
varying rate of subsidence over different areas would also affect the character of the
deposits. Where the rate was greatest, deep-water or marine conditions would he
more prevalent, and where the rate was slow shallow-water conditions would pre-
vail generally and coal beds would he more frequent. If the rate of subsidence over
the interior were constantly greater than that over the marginal area the firsl formed
ami lowesl beds would gradually acquire a westerly dip, while the upper beds were
horizontal, and the aggregate thickness of the deposits would be increased toward
the interior, although the thickness of an individual stratum, or of a heterogeneous
deposit formed during any interval of time given, would he thinner, proceeding from
margin to interior, [f subsidence were arrested along the margin and continued in
t he interior, t he deposits would thin to a feather edge along this margin. On the
other hand, if t here were elevation along t he margin and subsidence in t he interior,
the succeeding deposits would thin out within what were previously the marginal

118 PROCEEDINGS OF WASHINGTON MEETING.

limits and would abutagainst the underlying strata, [f subsidence were arrested in
the interior and continued over the margin, coal beds might be formed in the
interior which were not represented over the margin.

Figure 31 is an ideal representation of what would result with a certain sequence
of events of the character suggested. At B is a coal bed, originally horizontal,
which extended entirely across a submerged area before subsidence set in again.
At 6' is another bed which extended, however, only a short distance before being
submerged. At A is a third coal bed winch had a longer period of growth than ( ',
but which was also cut off by a sinking of the strata. From the divergence of the
lines .1 and />' it is evident that the rate of subsidence was greaterover the interior
than at the margin. Before the deposition of the bed B the margin at .1 was ele-
vated and the depression in the interior continued, and these opposite movements
were kept up during the periods of accumulate >n of tin' strata E and F and of those
intervening between these. The next section (figure 32) represents the same group
of beds after they have been elevated above, the water, so that the upper beds are
elevated some 4(10 feet above the extreme margin. It is, of course, impossible to
represent in any such diagram the infinitely complex association and the varied
succession of strata which resulted from all the combinations of conditions which
probably prevailed during the deposition of the .Missouri ( loal Measures, but, always
allowing for the great distortion of thicknesses and of angles of dip and slope, tins
diagram will probably suggest all of these.

The careful study of the above outlined hypothesis and of the last diagram will
show that it is calculated to satisfy fully all of the conditions enumerated on page
114. Such a study will reveal :

a. Flow a moderate amount of erosion might suffice to produce the present limita-
tions of the upper strata.

//. Why coal beds are more abundant over the marginal area.

c. Why the interval between any two strata may be very different at different

points.

<I. Why a columnar section, constructed from outcrop measurements of succes-
sively exposed strata from margin to topmost layer, will not represent the succes-
sion of rocks in such a section as 0 (>, in figure 7.

e. Why a coal bed may at different points immediately overlie strata which are
widely separated from each other in some exposed section, and hence why two
separated outcrops of the same coal bed may easily be mistaken for outcrops of
two different beds.

/'. Why the strata cropping out along the margin are not necessarily the lowest
beds, even though they dip toward the interior, and why beds encountered at the
base by drilling in the interior may be of earlier age than these marginal beds.

</. That the arenaceous character of the marginal deposits is an essential attrib-
ute of their location and not one of their age, and that sandstone, shale, or lime-
stone may be prevalent among the upper or lower beds of the Coal Measures
according as they were marginal, shallow-water, or marine portions of the deposit.

Something like a true section of these Foal Measure strata may ultimately be
constructed by the present state survey after all the many sections and records
obtainable have been studied and correlated. Until then we must proceed with
extreme caution, with the anticipation that all the intricacies of deposition which
the conditions herein referred to call for may exist and will have to be traced.

Figure 31 — Lleal Illustration of the Accumulation of the Coal measures.
Representing the results of successive cycles ol deposition. Vertical scale greatly exaggeratei

101 re 32— Jdi al /,'< presentation of thi M> ouri Conl Measures.

(119)

120 PROCEEDINGS OF WASHINGTON MEETING.

From the actual connection between the Missouri coal fields and those of Iowa,
Kansas, and Arkansas one would expect to find similar conditions there, and such
indeed is the case. Hall,* in describing the Iowa Coal Measures, says: "We must,
therefore, be prepared to find ultimately that the Coal Measures, or at least the
productive portions of that formation, thin out in great part or entirely in that
direction [toward the interior], while the calcareous port ions, which are of marine
origin, will be found increasing in force." C. A. White f describes the shallow seas of
the Coal Measure period as ending well south of the northern line of the state, and
refers to the thickening of the formations toward the center from the border,!
though he is of the opinion that " the coal-producing strata passed entirely beneath
the unproductive ones and do not disappear by thinning out as they do in the
opposite directions." $ Keyes, in writing of the stratigraphy of the Iowa Coal
Measures, described the gradation of shales into sandstones on the one hand and
into coal on the other. || The coals, he says, are not in continuous layers over the
wdiole area, but in lenticular patches;^ and he estimates them of little value for
general coiTelation.

Similar conclusions may also be drawn from the phenomena of neighboring
regions. Thus, Newberry, in describing the Coal Measures of Ohio, states that
the upper coals never reached so far as the lower ones, as they have been found
only in the center of the basin.** He also refers to the great variation of the
intervals between coal seams, and in general terms suggests an unequal sinking of the
area in explanation. He also described the coal basins there as of limited extent.ff
Orton, in writing later of the Ohio coals, states his opinion that the later coal beds
never extended over the outside margins of the earlier swamps, and in explana-
tion be suggests a simultaneous rise of the border and a sinking of the interior.! t
All coals below the Freeport, and others, he states, were apparently formed as
marginal swamps, and, with reference to the general question, he concludes : " If
we see reason to believe that these lower seams originated in marginal swamps.
with the sea near at hand, then, of course, we abandon the older view that
the coal seams extend indefinitely toward the center of the basin. . . . We
should expect to find the interior of the basin filled with terrain mort." \ \

I. C. White, in his recent description of the stratigraphy of the bituminous coal
fields of Pennsylvania, Ohio and West Virginia, states that though valuable coal beds
are found in the central portion of the trough, it is t rue, as a general law, that the coal
beds of this series (the lower Coal Measures) are thicker and better and more
numerous around the margins of the Appalachian field than toward the center, and
he states the same concerning the coals of the Pottsville conglomerate. || ||

As early as 1872, J. J. Stevenson, in describing the upper Coal Measures of Ohio,
Pennsylvania and West Virginia, referred to the disappearance of strata and the

* Report Iowa Geol. Survey, 1858, part 1, page 135.

t Report Iowa Geol. Survey, 1870, vol. 1, page 227.

t Op. Cit., p. 250.

gOp. cit., p. 259.

|| The Stratigraphy of the [owa Coal Measures: Bull. Geol. Soc. Am., vol. 2, p. 282.

If Op. cit., p L'sl

** Report Ohio Geol. Survey, neology, vol. i, 1874, p. 117.

tfOp. Cit., p. 1GG.

% % Report Geol. Survey of Ohio, L884, Economic Geology, vol.5, p. 135.

fJgOp. cit., p. 137.

[| |! Bulletin 1T. S. Geological Survey, no. G5, 1801, pp. 100, 181

AKTHTJB WINSLOW — THE MISSOURI COAL MEASURES. 121

merging of one into the other with a consequent coalescence and bifurcation of coal
beds* Again, in L874, in a paper on the parallelism of coal beds, he adduced many

instances of coal beds dividing, and concluded that all the coals of the upper Coal
Measures are offshoots from the Pittsburgh coal seam, formed by regular subsi-
dence and shorter intervals of repose, deltas and marshes being developed during
repose, yielding the minor coal beds, while during subsidence the marsh advanced
up the sides of the trough, forming the Pittsburgh bed.f Four years later, in a
chapter on the structure of coal beds forming part of a report on the Ligonier valley,
he again stated the same conclusion, after introducing additional data.t;

The inference from these references is plain that the explanation of the process
of deposition in Missouri applies to other areas, and is doubtless of wide applica-
bility, at least so far as ( 'oal Measure deposits are concerned, and perhaps with regard
to other formations.

The next succeeding paper was read by title :

THE WELLS CREEK BASIN AND UPLIFT IN STEWART AND HOUSTON

( '< (UNTIES, TENNESSEE.

BY JAMES M. SAFFORD.

The following paper was then read, the objects described being ex-
hibited :

THE PELVIS OF A MEGALON YX AND OTHER BOXES FROM BIO BONE

• 'AVE, TENNESSEE.

BY JAMES M. SAFFORD.

( 'ontents.

Introduction , page 121

The first known Pelvi9 of Meyalonyx 122

Other Bones of the Collection 122

Bones of Megalonyx previously obtained from Big Bone < !ave 123

Location and History <>r Big Bone Cave 123

Introduction.

In September, L886, Mr. A.J. Denton, of Henderson, Tennessee, brought a box
of hones to Nashville and left them for my examination. A letter was received
from Mr. Denton concerning them, from which I take the following extracts :

"They were ion ml in :i cave in the Cumberland mountains, Van Buren county, Tennessee, * * *
tin- cave in which were found some very large bones about fifty or sixty years ago, and which are
now in ;i museum in Philadelphia. * * * The Imuh-s lefl for you were discovered in issi by a
laborer who was digging the so-called guano (bat manure) in the cave. * * * They were covered
to a depth i.t' aboul three feet, and were Ij Lng in such position as t" show they had never been dis-
turbed. The I mm. I. vertebrae and hip bones were in the position which they would necessarily have

"The Upper Coal Measures West of the Alleghany Mountains: Trans. Amer. Lyceum of Nat. Hist.
hi' New York, vol. \. 1872, pp. 226-252.
fOn the Vlleged Parallelism of Coal Beds: Proc. Am. Philosophical Soc, vol. xi\. 1874, pp.
!95.
!nd Geol. Survey of Pa., K K K, 1878, pp. 283 303.

XVI— Bui i. CtKor,. Snc. \\t.. Vol. ::. 1891

122 PROCEEDINGS OF WASHINGTON MEETING.

after the decay of the animal, showing it ("have been about eighl or nine feet long. They created
considerable interest among the people in the neighborhood, but no oqi iM give even a reason-
able conjecture as to the kind of animal. Tl ther bones (those of the skeleton not in the box)

were decayed or crumbled immediately after being exposed to the air."

The bones were found to be those of Megalonyx. They were purchased from
Mr. Denton and are now the property of Vanderbilt University, at Nashville.

Tjie first known Pelvis of Megalonyx.

Especial interest is attached to these bones, as the lot includes, fairly well pre-
served, the major part of the pelvis of the animal — enough of it, indeed, to give a
good idea of the character and general form of the part, which, it appears, has
heretofore been unknown. Mr. E. W. Claypole, in a full and very satisfactory
article on Megalonyx and allied forms, published this year in the February and
March numbers of the American Geologist, makes the statement that " no pelvis
has yet been found, with the exception of a fragment or two." From this I infer
that the specimens now presented will be new to paleontologists.

The parts of the pelvis found are :

The two ilia.

Right pubis (a portion).

Right ischium (a portion).

The five sacral vertebrae (some broken).

The ilia are broad and fan-shaped. Their thickened margins, like parts of
nearly all the bones of the collection, are to some extent gnawed by some small
animal, probably a rodent. The portions of the pubis and ischium, when fitted
in place to the right ilium, reconstruct well the right acetabulum, showing both its
form and dimensions. The general form of the pelvis of the MegtUony x, as indi-
cated by these specimens, recalls strongly that of Megatherium. There lias been no
opportunity, however, for any detailed comparisons.

Other Bones of the Collection.

The bones of Megalonyx associated with the pelvis are as follows :

The skull.

Fragment of a rib.

Right humerus.

Right scapula (most of it).

Left tibia.

Seventeen vertebra? (including the sacral).

Fragments not determinable.

These bones are in various degrees of preservation. Some have lost one or more
epiphyses. On some, portions of cartilage and tendons still remain. The animal
to which they belonged was doubtless young.

It is not my purpose to describe the individual hones. I only add a note as to
the skull: Its length, from the occipital condyles to the anterior margin of the first
molar alveoli, is 13 inches and :; lines, a length the same as that of the specimen
from Natchez, Mississippi, referred to by Dr. Leidy in his memoir on the extinct
sloths in the Smithsonian Contributions, published in 1853. The teeth are entirely

J. M. SAFFORD — THE PELVIS OF MEGALONYX. 123

gone, with the exception of some fragments left in the sockets. The cheek hones
are mostly gnawed away. In other respects the skull is in a satisfactory condition
for study.

Bonks of Megalonyx previously obtained from Big Bone Cave.

Mr. Denton, in the letter from which I have taken extracts, refers to the finding
of large hones 50 or 60 years ago in Big Bone cave, and further says that they are
now in Philadelphia. These doubtless are the hones which form one of the col-
lections used first by Harlan and then by Leidy in their descriptions.

I give below a paragraph from Dr. Leidy's memoir, and for two reasons: First,
because his description of the state of preservation and condition of the bones of
the collection he had would answer as well for those of the lot discovered recently,
and now presented to a scientific body for the first time; secondly, because the
hones he enumerates so nearly supplement the list I have given. With these facts
before me, and both lots coming from the same cave, I thought at one time that
the bones of both must belong to the same animal, and 1 am not certain yet but
that it will so prove upon bringing both collections together. Dr. Leidy, in enum-
erating the specimens of Megalonyx available for study, says:

"A collection oi bones of a young animal, nearly all of them having the epiphyses detached:
They are the left scapula, imperfect; the left os humeri without epiphyses, the right radius without
its distal epiphysis, tin- proximal two-thirds of the right ulna, the right os raids, the distal
epiphysis of tie' right os femoris, the left tibia without its distal epiphysis, the distal epiphysis of

the right tibia, lumbar vertebra, four dorsal vertebras with one exception without epiphyses,

fragments of three right ribs, fragment of a loft rib, and two ungual phalanges of the right hind
foot. These were found in Big Bone cave, Tennessee. Thoy are of a yellow color, comparatively
light, unchanged in texture, and quite recent in appearance. Several of them are remarkable for
retaining portions of the articular cartilage, periosteum, and tendinous attachment; and one ungual
phalanx has the nail preserved upon it almost entire. They also present the marks of having been
gnawed by some rodent."

Location' and History of 1*>h . Bone Cave.

Big Bone cave is in the base of a westward-jutting spur of the Cumberland moun-
tains, in the northwestern corner of Van Buren county. It is a little east of a
straight line joining McMinnville and Sparta, and not far from midway between
the two places. The spur above divides the valley of Cany Fork river from that of
Rocky river. The cave, like many others in Tennessee and Kentucky, is in the
lower Carboniferous limestone. It has long chambers in which there was once
much saltpeter earth. In L811-12 the most accessible part of this earth, running
in half a mile or more from the month, was dug and leached in the process of
making nitre. This was at the lime a great industry, and quite a village was tem-
porarily built up around the mouth of the cave. It was during the period of this
work that the huge bones were found and suggested the name by which the cave
litis ever since been known.

Remarks were made by Professor E. D. Cope.

124 PROCEEDINGS OF WASHINGTON MEETING.

The next paper read was entitled —

NOTES ON THE CRYSTALLINE ROCKS OF CENTRAL TEXAS, WITH MAPS.

BY THEODORE B. COMSTOI K.

Remarks were made by Professor ('. R. Van Hise, to which the author
replied.

The following paper was then read :

THE CIENEGAS OF SOUTHERN CALIFORNIA.
BY EUGENE W. HILGABD.

A cienega, in the parlance of the native Californian, is a limited area showing a
growth of water-loving plants, appearing sporadically in otherwise arid surround-
ings— usually hillsides or valley margins — and occasionally giving rise to flowing
springs. The economic importance lately attained by these cienegas as sources of
irrigation water by the aid of artesian borings, and some peculiarities of structure
upon which their occurrence in that particular region seems to depend, justify at
least a brief presentation of the facts to this body.

A simple and typical case in point is presented, for instance, by San Antonio
creek, a stream issuing from a canon in the Sierra Madre near the town of Pomona.
in the San Bernardino valley, Los Angeles county. It is near the present divide
between the adjacent drainage basins of the San Gabriel river on the west and the
Santa Ana river on the east. Though a small stream, carrying only from 700 to SOD
miner's inches of water in summer time, it has formed in front of its exit from the
canon a debris cone or" fan " having a radius of seven or eight miles, of which the
apex, near the canon mouth, is between 400 and 500 feet above its base. On the
slopes of this fan, as well as near its base, there appear numerous cienegas, some
less than an acre in area, while others range up to twenty acres and over. In some
of these, large sycamore trees art' the only unusual indication amid the " bee-pas-
tures" of white sage, cactus and other plants characteristic of the thy mesas of the
south. In others there is added the willow and clumps of "tule" (cat-tail) and
other swamp plants. From some, springs issue naturally ; in all, shallow dug wells
find water; in many of them, artesian bores have been made with good success*
The deposits penetrated in these bores are, of course, such as may be expected in a
debris-fan ; but they vary so quickly and completely in wells only a short distance
apart as to show that the ancient portions of the fan have been formed under a
regime exactly like the present — namely, an alternation of very coarse deposits of
gravel and large cobbles such as are now carried by the si ream during the torrential
Hoods to which the high ranges are subject, with fine silt and even clay, which are
practically impervious to water. The abrupt diminution of velocity on emergence
from the canon results in the quick accumulation of cobble ridges or "karnes,"
winch sometimes change the main channel, within a k'\\ hours, to a totally differ-
ent direction. It is obvious that in past times such changes of channel have thrown
the water of the creek from one drainage basin to the other ; at present it discharges
toward the Santa Ana basin, but unless artificially prevented there is no reason why
it mav not some time revert to the San Gabriel watershed.

E. W. HILGARD — THE CIENEGAS OF CALIFORNIA. 125

If we imagine the structure that must result from such a mode of accumulation of
a debris-fan, the spi iradic appearance and peculiar localization of the cienegas 1 1 >eing
the points at which the water fed into the coin' at the mouth of the canon is forced
near tu the suface either by a cross ridge or by the termination of a water-bearing

cobble-'bed underlain by an impervious layer) is easy to understand. But it is also
obvious that the continued supply of water from the stream into the various old
channels of the debris cone must depend upon the maintenance of the open gravel
surface at the apex of the cone. When this is wholly or partially closed, whether
by natural or artificial processes, then, the source of supply being stopped, the
springs or artesian wells dependent upon it must diminish or cease to flow. Such
variations and stoppages have already been experienced at several points, and as
they may prove very costly, if not disastrous, to heavy investments already made,
it is quite important that the need of keeping the area of infiltration open for the
winter floods should be fully understood by the populations concerned. When
this is attended to it is obvious that we have here natural storage reservoirs for Hood
waters, annually replenished and likely to be fully refilled each season, no matter
how heavy may have been the drafts made upon them during the preceding irri-
gation season.

The most extensive example of del iris-fan storage of flood waters thus far known
to me occurs in the upper San Bernardino valley, at the head of which two large
streams — the Santa Ana river and Mill creek — emerge from narrow canons, at
whose outlets there are truly phenomenal accumulations of huge bowlders, which
in time of Hood are tossed about by the torrents with a thundering noise sometimes
audible miles away. Here are many square miles of open cobble surface, into
which flood waters can be and are absorbed with the greatest ease, although in the
usual channels of the summer flow the bottom is made sensibly waterproof by finer
sediments. Costly tunnels have been driven through these cobble-beds under the
impression that large amounts of water could be thus collected; but while the con-
stant drip proves the perviousness and absorbent nature of the deposit, that very
circumstance prevents the gathering together of any very large supply of water
in the relatively insignificant areas of the artificial drifts.

From the head of the d6bris-fan of Mill creek to its base, near the town of San
Bernardino, the distance i> between 12 and 14 miles, according to the initial point
chosen; the fall of the surface within the same distance is between 600 and 700
feet. The average width of the valley is about 10 miles, and artesian borings have
shown the gravels and cobble to be nearly a thousand feet in thickness within a
mile of the southeastern edge. This enormous gravel mass, filled with water from
the floods of the two streams, forms a natural reservoir of such magnitude that the
drafts thus far made upon it by the numerous boreholes sunk in the lower valley have
failed to show an v such degree of mutual interdependence as is usually observed in

wills situated short distances apart — a fact which I have ascertained by experi-
mental measurements made under proper conditions. This relative independence
of the flow of contiguous wells also indicates that the water-bearing stratum con-
sists of gravel so large and so open that the water mass may be considered as exert-
ing its pressure rather freely in all directions; yet on reopening a closed well there

always exists a material accumulation of pressure, which takes several hours to

recede In its normal amount .

besides the artificial outlets mentioned, however, there is a number of natural
outlets on the slope of this greal gravel reservoir. The mosl conspicuous is the

126 PROCEEDINGS OF WASHINGTON MEETING.

source of Warm creek, the stream which has been appropriated for the purpose of
irrigating the well-known colony of Riverside. Warm creek has no visible connec-
tion with any of the streams that descend from the Sierra Madre; it rises in the
valley itself, fully three- miles away from the foot of the range. There is no obvious
reason for its being there, but the water gathers from little rills and ditches within
a space of about a quarter of a mile, acquiring within that distance nearly its full
volume of from 2,000 to 2,500 inches during the dry season. At other points, also,
"artesian" springs rise with considerable force and volume, and in the immediate
floodplain of the Santa Ana river, rivulets gather at many points on the margins,
at the foot of the bluff, some 7 or 8 feet above the river channel, and How toward
the latter to increase the volume of the stream. It thus happens that "the entire
flow of the Santa Ana river" has been appropriated at at least three different
points, each appropriator receiving a good flow, and that in the absence of any
obvious important additions from incoming streams. As maybe supposed, bore-
holes sunk in this region of spontaneous flows encounter at very small depths (from
120 to 150 feet) very copious flows of artesian water, in cobble-beds; while near the
border of the valley not only is a greater depth required and the outflow less, but
the materials penetrated are much flner.

Since the terraces of reddish loam that border the foot of the Sierra Madre from
the head of the valley to the San Gabriel river indicate plainly that the subdivision
of the valley into two drainage basins is a comparatively recent event, it does not
seem improbable that the artesian reserve referred to might be tapped by deep bor-
ings much farther westward than has heretofore been attempted; perhaps within
easy reach of the city of Los Angeles.

A very striking exemplification of the origin of cienegas exists in the valley of
Temescal creek, one of the southern affluents of the Santa Ana river, in San Ber-
nardino county. This creek is really the natural continuation of the San Jacinto
river of San Diego county; but an intervening lake basin (Lake Elsinore) pre-
vents actual flow from the latter stream to the Temescal valley, save in seasons of
extraordinary rainfall. Its water is supplied almost entirely from the canons of
the Santa Ana mountains, which have a rather copious rainfall in their higher por-
tions. At the head of the valley there is a small lake | Lee lake), which, with no vis-
ible inflow, nevertheless has at its lower end a steady outflow of about 400 miner's
inches of water during the dry season, thus forming part of the water-supply of the
"South Riverside" colony. Examination shows that the lake is ted entirely by a
series of springs, or rather an almost continuous ooze, from the enormous masses of
granitic and other debris that have' accumulated in front of the two uppermost
canons of the Temescal valley, and which reach entirely across the valley to the
foot of the (Temescali range opposite. These debris masses are so porous that actual
surface flow very rarely occurs, and no well defined bed for a stream exists save
where, close to the lake basin, the materials are relatively line. Evidently the main
body of the rainfall gathered into these canons is stored in the coarser portions of
the debris-fans above.

Below this lake basin the Temescal valley is divided lengthwise by a series of low
ridges formed of materials mostly impervious to water, of Tertiary age. In from
of the canons of this lower portion of the valley similar great debris masses have
accumulated also: but since the impervious ridges mentioned prevent the outflow
of water save during actual freshets (when small streams pass through gaps in the
ridges), extensive cienegas have been formed between the valley ridges and the fool

E. W. HILOARD — THE CTENEGAS OF CALIFORNIA. 127

oftheSanta Ann range. In these, as in the upper San Bernardino valley, "arte-
sian " springs rise at many points, and vegetation remains bright green all summer.
Borings thus far made have developed a very copious artesian flow, and a tunnel
driven through one of the clay ridges toward the cienega was suddenly inundated
when its face reached the gravel of the debris mass, about 40 feet below the surface.
The artesian wells and natural surface flow from these cienegas, so far as developed,
yield an aggregate flow of nearly GOD miner's inches, which can doubtless he mate-
rially increased; and this, with the flow from the lake above, constitutes the water
supply for the colonies below.

These examples, which could be greatly multiplied, show sufficiently both the
nature and origin of the cienegas, and also their practical importance as sources of
water supply, which calls for a more careful survey of their extent of occurrence
than has heretofore been made. While they do not render the establishment of
artificial storage reservoirs superfluous, they do supplement them locally to a very
material extent, rendering it possible to occupy for agriculture huge areas that
otherwise would have remained arid for many years to come. But there arises the
question as to the geographic limits 'within which these natural storage reservoirs
may reasonably be sought, for it is notorious that they are not usually found, and
the name and idea of the cienega is not generally known, in the northern portions
of California.

The essential condition of cienega formation is manifestly the opportunity for the
abundant formation of deposits of exceptionally coarse and pervious; gravel and
cobbles near the points where the canons emerge from the mountains. This, again,
is necessarily conditioned upon the occasional occurrence of violent, torrential rain-
fall in the mountains, alternating with periods when quiet deposition allows of the
formation of water-shedding layers. Another condition appears to be the ready
weathering of the parent rocks into rounded forms, by winch close packing is pre-
sented, so that abundant interspaces are permanently maintained.

Both conditions are fulfilled to an unusual extent in the granitic ranges of south-
ern California. The rock is rather easily disintegrated, firsl into larger and then
into smaller rounded masses, from which large quantities of very coarse angular
sand have been detached, and which continue to disintegrate rapidly when exposed
to the air, but are relatively stable when submerged in the debris mass, and SO
maintain porosity. Such granitic or granitoid material forms the main bodyofall
the larger cienegas I have examined in southern California ; and the remarkably
large proportion of potash contained in their waters in consequence is of no small
economic importance.

li is therefore reasonable to presume, and it seems d priori probable, that a
concurrence of the two conditions, climatic and petrographic, is requisite for the
formation of cienegas upon a practically useful scale ; and the extent to which this
concurrence actually exists, geographically, is a question of do little practical in-
terest.

Professor Hilgard's paper was discussed by Professor C. K. Van Hise.

L28 PROCEEDINGS OF WASHINGTON MEETING.

The next paper was on —

111-: ( IIATTAHOncilKK EMBAYMENT.

BY LAWRENCE C. JOHNSON.

Looking upon :i map of the Gulf of Mexico one prominent feature, certain to at-
tract attention, is a deep bight running up into middle Florida, called Apalachee
hay. During Miocene time the coast line was very different. The continent on the
Alabama side extended down Chattahoochee and Chipola river- to the vicinity
of Chipola, or so as to include part of Jackson county in Florida. The Mariana
building stone, which is an orbitoidal limestone of the Vicksburg type, formed the
shore during this period. To the eastward at the same period the continent did not
reach into the peninsula. The shallow Miocene sea, however, toward the south
was close set with Eocene islands in the Suwanee region, their sites now marked
by the distinctive deposits of the phosphate belt.

Erosion in the valley of Suwanee liver and in its western hranches exposes
the Eocene orbitoidal limestone in many places, and. strange to say, of a type
slightly differing from that of the west, but resembling that of Cooper river, South
Carolina. Between these two limestone headlands of the Miocene period lie the
greater portion of the counties constituting what is known as middle Florida.

To avoid conflict with a mountain nomenclature, this ancient extension of the
hay of Apalachee may he called the Chattahoochee embayment. The Chattahoochee
river doubtless poured into the head of it on the northwest, and constituted then, as
it still constitutes, the principal contributor of material for its sediments.

The general appearance and character of the rocks and fossils of this embayment
stamp them with a unity of type. The rocks are all limestones, hut generally so
impure as to be often almost sandstone. The older of these beds are more compact
and harder than the Vicksburg rocks, and even where not silicified and where not
a mere calcareous sandstone the fossils do not retain the original shells imbedded
in a softer matrix, but have their lime leached out and their cavities often filled with
calcite. These rocks, then, are more insoluble, more unyielding, than other known
orbitoidal limestones. Upon this fact depend many of the phenomena of this part
of Florida.

Though spoken of as displaying a unity of type, it not intended to treat the rocks
and fossils of the Chattahoochee embayment as identical throughout ; there are
variations, which may be exhibited by sections.

Considering the embayment as having become dry land by the usual process of
continental uplift, there is to lie anticipated a general dip toward the south,
and observations show as much. Recent studies in Florida have brought out an-
other fact, viz, that there is a westerly dip toward the axis of the embayment. This
is very obscure in the eastern part, but very manifest in that nearer the Chatta-
hoochee river. As a consequence, there is a thinning out of the strata eastward
and northward, and a deepening of accumulation toward the west and south. The
southward dip is well shown on the river. Descending the river, the last seen of
the Vicksburg rocks is about Port Jackson, a short distance above the mouth of

L. C. JOHNSON— THE CHATTAHOOCHEE EMBAYMENT. 129

Flint river; the next rocks seen are at the <>1<1 Chattahoochee landing, on the road
to the village, and it is upon these that Mr. Langdon founded the Chattahoochee

formation. The northern and eastern extension, in exactly this form, has not yet
been determined. Southward it lias a very considerable inclination, so that in-
stead of covering high hills, as about Chattahoochee, it sinks to the place of the
lower rocks at Aspalaga landing and goes out of sight at Rock bluff.

Fossils are not common in this basal portion, and their place is usually filled with
calcite ; and the rock is of considerable weight and density. At Aspalaga, however,
a layer near the top is tilled with casts and impressions of gasteropoda and coral.-,
including conspicuously the large Orbitulites floridana.

This phase of the formation constitutes the upper or country rock of Gadsden
county. It is largely exposed on Little river and its branches. It is of interest as
the bed rock upon which lie the phosphates of this county, notably at Aspalaga,
where the top of this layer is 40 feet above the water; above lie as much more of
brown and dark-colored clays or altered marls, with thin layers of shells; all very
much decomposed except an Ostrea and a large pecten (Pert, n madisonius) resem-
bling that of Waldo, on the eastern side of the peninsula. For the sake of distinc-
tion, we may call this upper bed the Aspalaga* phase of the Waldo formation.

The following section displays the relation of the beds at Aspalaga (on Apalachi-
cola river, in section 35, township 3 north, range 7 west) :

Feet.

1 . Pine level with much gravel in poor sand jTO

2. Sands of number 1 washed off in places expose a very hard red clay alter-

nating in places with ferruginous sandstone, forming cliffs ; some also pure
enough for limonite 20

:!. Stratified sands and sandy clays, water bearing, having springs at the base

and in intercalated clay beds % 50

4. Tough calcareous clays, including the residuum after lime of the shells is

leached away, generally dark colored % 60

5. Limestone forming bluffs for over two miles, unevenly scored by erosion ;

rising higher toward north, subsiding toward south; passes beneath the
river at Kock bluff, though very high at Chattahoochee || 40

At bock bluff, live miles south of Aspalaga, the heavy rocks of the Chattal -

chee lie below the water line. The clays of number 4 of the preceding section
are lien- much reduced, while the stratum itself increases in thickness and carries
more of 1 he calcareous sand, with numerous well preserved pectens and other shells.

* Tin ■ old site of Aspalaga village and posl office is in section 35, township :'• north, range 7 west.

Rock bluff i- on I hattahoochee river, 5 mil ss south of Lspalaga, Chattal :hee being iboul the

same distance norl hward.

t Elevations ind thicknesses ascertained by aneroid.

J 2 and 3 may be assigned to the Lafayette formation.

g Exposure no! clear enough to ->•■• subdivisions, bul in gullies some dec lyed shells are found,
well .-I- Pecten and Ostrea which resemble forms found at Waldo; al one spol in a trough of num-
ber 5 a phosphate bed occurs. This member may be called the Aspalaga clays.

[n the lower layers the fossils are obscured by infiltration of calcite; the upper layers are full

i>i fossils, corals, and lamellibranch, and Orbi ulites lloridana. \\ M it Pleasant thi- upper layer

i~ found o\ er i" < feel ■*■••% e the ri

XVII Bum '■! "> Soi . Am., \ oi , 3, 1891.

130 PROCEEDINGS OF WASHINGTON MEETING.

A section in the vicinity (on Sweetwater creek) where phosphate beds occur in

or above this calcareous soft sandy rock well displays the relation of the members

in this part of the Chattahoochee embayment :

Feet.

1. Columbia sands of river origin ; variable in thickness on account of ero-

sion ; wells at top of ridge give 20

2. Alum bluff or Chipola marl ; at this point less than *15

3. Aspalaga marl;f pectens and oysters in gray calcareous compact sand,

with darker clay at base 20-40

4. Aspalaga phase of Chattahoochee formation, or the upper layer extending

eastward over high lands of Gadsden county; fossiliferous ; estimated

to be " 30

5. Lower portion of Chattahoochee formation, generally without fossils;

more calcareous than number 4 ; calcite in cavities ±40

6. Place of supposed underlying Vicksburg rocks not seen on the river, south

of Port Jackson, above the mouth of Flint river

In this section a thin layer of another variety of sands and clays appears, cover-
ing the gray sandy limestone of the pecten-bearing beds and covering the peculiar
phosphates of this region. It is doubtless an overlap from Alum bluff of the Chip-
ola deposit. It may be traced westward and northwestward into Alabama, on
the waters of Yellow river ; but eastward it stretches little beyond Ocklocknee
river, after crossing which it becomes lost beneath the later formations on Lost
creek and Sopchoppy river. The overlying beds (number 3 of the section) extend
up Ocklocknee and Little rivers some distance, and still further eastward into south-
western Leon county and the northwestern part of Wakulla county. Between
Alum bluff and the Gulf the formations and their relative proportions have not
yet been determined.

Thus, a great part of Jackson county, as well as all of Calhoun, Gadsden, Liberty,
and Franklin, with half of Wakulla and the southwestern part of Leon counties.
Florida, constitute the Chattahoochee embayment in its most restricted sense.

In addition to the geologic structure, there are superficial characteristics by
which the embayment may generally be recognize I : < didsden county has very much
the appearance of the high, rolling pine lands, its natural forest covering being a
mixture of oak and hickory, which prevails in the adjoining state- of Alabama and
Georgia. It abounds in springs and running streams ; there are no lakes, and none
of the sinks so common in other parts of Florida. In all this more restricted em-
bayment the lakes, springs, and sinks prevailing in the eastern portions of middle
Florida form no part of the topography : because, first, the most soluble and cav-
ernous rock of the region (the Vicksburg limestone) lies deep beneath the surface.
probably little, if any, above tide ; second, the impure limestones are little soluble ;
and, third, the later beds are of great thickness.

*This deposit runs southeastward to Ocklocknee ami southward to tin' mouth of the river, and
westward and northwestward to Alabama, with a thickness of I i el

fThe phosphates are in or over this deposit.

I It is estimated, from observations at Aspalaga and Chattahoochee and other places north of Rock
bluff that the thickness "1 these two exceeds 100 feet.

L. C. JOHNSON — THE CHATTAHOOCHEE EMBAYMENT. 131

Defined in a more extended sense, the Chattahoochee embayment will stretch out
almost to the basin of Suwanee river, or at least to about the middle of Madison
county. The rocks found in this extension present quite another aspect. When
collections were first made in this part of Florida a few years ago, the leading type
was called the Wakulla formation because it abounds in the vicinity of the springs
of 1 hat name. The material was taken out of a deep well two miles southwest of Tal-
lahassee. The leading features of this rock were an abundant Hemicardium (species
not determined so far as the writer is aware) and the large Orbitulites floridana, to-
gether with many land shells. The rocks vary greatly in material ; sometimes a
quite pure limestone, at other places, or in other layers, aluminous and silicious. The
collection from the well shows a good limestone, with calcite filling the cavities left
by removal of the suhstance of the shells, and with some lumps or streaks of chert ;
the deposit was said to be 80 feet thick. Two miles northwestward and one mile
northward there are hills fifty to one hundred feet higher, covered with Lafayette
sand.

The excavation at the Saxton mine, 3^ miles west of the court-house in Tallahas-
see, reaches this rock, and is interesting because showing that here again its surface

is the place of phosphates. The section here is as follows :

Feet.

1 . Soil and subsoil (Lafayette sand) 6-10

•_'. ( heenish plastic clay ; stands high heat ; has a few nodules of hard phos-
phate ; of doubtful genesis 1"

:;. A compact, friable sand, very white and pure ; of doubtful genesis 6-9

■i. Dirty clay, with nodules of phosphate and rotten leaves; also of doubtful

genesis 3

5. Sandy clay, colored by organic matter, leaving fragments of fossils all

leached away except a chalcedonized Ostrea li

(i. Whitish sandy clay, phosphatic, with lumps of pure white clay 8

7. Yellowish white clay, phosphatic, sandy, with peculiar irregular masses of

very hard phosphate* 12

s. Bed rock, dug into only 2 feet ; soft, pure limestone without fossils, corre-
sponding with first rock struck in well l' miles southwest and 50-100 feet
lower; fossils identified with those of the Wakulla beds; similar to
those of Weelaunee and Lloyds

In this part of Florida the great springs or - rises" begin near the coast, ami far-
ther back in the higher ground numerous sinks ami lakes occur. This is undoubt-
edly because the strong, insoluble sandy or aluminous limestones thin out, as do
the overlying impervious clays, so thai there is nothing to prevent infiltration of
surface waters, and thus the formation of sinks and subterranean rivers in the

porous lime-tones of tl Ider formations. When the sinks or outlets are stopped,

or partially so,lakesand ponds, or at least funnel-shaped depressions take their places.

An actual section taken where (lie later rock and the superficial Covering are sulli-
Ciently thick to prevent sinks will illustrate the relation. A deep excavation at
Weelaunee, Jefferson county, Florida (sections :;.". and 36, township 1 south, range
I east), gives the following succession :

♦ The majrix of 1 iber7 i said to run IG% per cent and th« rough, hard nodules 80 per cent of

phosphate "i linv

132 PROCEEDINGS OF WASHINGTON MEETING.

Feet.

1. Well-defined Lafayette sand, as seen on St. Augustine road and northward

to Monticello ; water-bearing 40-60

2. Solid, impervious sandy clays, very dark red ; seen in washes; pierced in

deep well at Weelaunee; no fossils, no stratification lines, but traces of
both ; not water-bearing* 30-50

0. Limestone, sometimes pure, sometimes very impure ; full of fossils, among

them Orbitulites floridana, a Hemicardium very numerous (species un-
known), and many shells of Helix, Pupa, and other land snails ; burnt
for quicklime at Weelaunee; considered equivalent to Wakulla rock of
Tallahassee and Lloyds, and there approaches 100 feet ; here penetrated
in Weelaunee excavation (without getting through ) 50

Between the locality of the above section and Tallahassee the St. Augustine road
crosses that part of the depresssed surface, south of Chaires station on the Florida
Central and Pensacola railway, known as the "natural bridge of St. Mark river."
All around the surface sounds cavernous to the tread, and there are numerous sinks
in the vicinity.

From this part of the St. Mark country, at an ever-increasing distance from the
high hills of Lafayette sand, diverges a low terrace of Columbia sands overlying
silicious limestones and sandstones of no great thickness ; and this arenaceous rock
crosses all the small streams which empty into Apalachec hay. beginning at Aucilla,
by natural bridges; and this ancient beach line marks the boundary in that direc-
tion of the Chattahoochee embayment in its most extended definition. On Fen-
ahollowa river only the bridge has been washed away, hut enough remains to iden-
tify the old natural structure and its locality.

A section at the natural bridge on Steinhatche.ee river (10 to 12 miles from its

mouth), the easternmost of the series, will illustrate the system; and will at the

same time well illustrate the relations of the older and the newer Tertiary rocks of

Florida :

Feet.

1. Sands resembling the Columbia 6

2. Impure silicious limestone, with a few fossils (as seen eastward at Howard's

sink and the big slough one mile east of river) ; the dip is westerly, and its

thickness increases from 2-4 feet to 8

:!. A sandstone (no fossils), thin and broken at Howard's I5 miles eastward:

getting thicker westward toward bridge ; probably 3

4. Hard sandy marl, full of fossils; among them a Spatangus and two echinoids,

at Howard's sinkf 2

5. Not seen at the natural bridge but well seen at Howard's sink, Ik miles east,

in the river, 1-2 miles north, and at 8-Mile creek, 4 miles northeast of bridge ;
a soft limestone easily eroded, filled with a Pecten (thought to be P. per-
planus) and innumerable reservoirs of Nummulites ( A", wttcoxi '.') 20

* In genesis this is believed to >»■ a leached, oxidized ami altered marl, a kind of formation com-
mon in Florida, and proposed to be called amurcaceous, from amurco, the residuum of fruit or
olive press — that is, where the insoluble material of a 1 >• - « I retains the place of original deposit, but
is altered by meteoric waters.

f These four members constitute the arch of the bridge. Tw iles north of the bridge the place

of number l is tilled by an Ostrea l>e,l lying upon number '<, the shells resembling O. virginiana.
Paleontologists are m>i com inced that the fossils of numbers 2, 3 and I of this section are Miocene;
they may represeni an upper layer of the Eocene (Vicksburg) limestone,

L. G. YATES — PECULIAR GEOLOGIC PROCESSES. 133

The following papers were read by title :

ON THE SEPARATION AND STUDY OF THE HEAVY ACCESSORIES OF ROCKS.

BY OKVII.LE A. DERBY.

This paper is published in full in the Proceedings of the Rochester
Academy of Science, volume I, 1891, pp. 198-206.

PECULIAR GEOLOGIC PROCESSES ON THE CHANNEL ISLANDS OF CALIFORNIA.

BY LORENZO G. FATES.

(Abstract.)

The eastward trend of the California coast south of Point Conception causes the
summer trade-winds to assume the same direction parallel to the coast. Since the
islands of the Santa Barbara channel have been largely denuded of their herba-
ceous vegetation by slice}) and cattle, the shore sands drift heavily to leeward, even
as far as from San Miguel, the outermost island, across a four-mile channel to Santa
Rosa. This sand ill Is the cavities left by decaying vegetation, and casts of trunks
of trees and shrubs are thus formed, which in the course of time consolidate, and
may hereafter puzzle the geologist.

THE PRINCIPAL MISSISSIPPI SECTION.

BY C. E. KEYES.

PROCEEDINGS OF THE SECOND SECTION.

The papers on glacial geology and the Pleistocene formations were
read in the Second Section, which met in room 14 of Columbian Univer-
sity, Vice-President T. C. Chamberlin presiding, and Professor Samuel
( ;il \ in acting as Secretarv.

Vice-President Chamberlin called Professor X. H. Winched to the

chair and read a paper entitled :

THE PRESENT STANDING OF THE SEVERAL HYPOTHESES OF THE CAUSE OF

THE GLACIAL PERIOD.

BY T. C. CHAMBERLIN.

This paper was discussed at length by C. II. Hitchcock, X. S. Shaler,
Warren Qpham, E. \V. Claypole, K. D. Salisbury , J. A. Holmes, and the
author.

134 PROCEEDINGS OF WASHINGTON MEETING.

Vice-President Chaniberlin resumed the chair, and the following paper
was read :

ON THE NORTHWARD AND EASTWARD EXTENSION OF PRE-PLEISTOCENE
GRAVELS IN THE BASIN OF THE MISSISSIPPI.

BY R. D. SALISBURY.

A second paper was read by the same author:

ON CERTAIN EXTRA-MORAINIC DRIFT PHENOMENA OF NEW JERSEY.

BY R. D. SALISBURY.

The two papers by Professor Salisbury (printed on other pages) were
discussed by C. R. Van Hise, Frank Leverett, E. W. Hilgard, N. H.
Winchell, F. J. H. Merrill, T. C. Chaniberlin, and the author.

The next paper was on —

INEQUALITY OF DISTRIBUTION OF THE ENGLACIAL DRIFT.

BY WARREN UPHAM.

Contents.

Discrimination of Subglacial and Englacial Drift page 134

Deposition of the Englacial Drift during the Departure of the Ice-sheet 137

Tracts of abundant Englacial Drift 139

New England 139

New York 140

Minnesota 140

Manitoba 141

Tracts of scanty Englacial Drift Ill

New England Ill

New York 142

Minnesota 142

North of Rainy Lake and the Lake of the Woods I I-

Relationship-of the Englacial Drift to the Terminal Moraines 143

Forms in which the Englacial Drift was deposited 144

Forms of Drift HI

Englacial Till 145

Perched Blocks L45

Kames 145

Osars or Esk'ers 14G

Valley Drift 146

Loess 146

Deltas L46

Influence of adjoining Lakes or the S ■ a 117

Discrimination of Subglacial and Englacial Drift.

The various drift deposits which are left to us as the record of the Glacial period
give far mitre information of the wane and departure of the last ice-sheet than of
its accumulation and stages of advance to its maximum area and depth. Thus we
fail to discover the beginning and successive limits of increase of the ice-sheet

WARREN UPHAM — DISTRIBUTION OF ENGLACIAL DRIFT. 135

until we find its extreme boundaries marked by the outermost of its numerous
approximately parallel terminal moraines; but the inner moraines, of which no
less than ten have been mapped by the writer in Minnesota and North Dakota,
and a larger number by Mr. Frank Leveret t in Illinois, Indiana, ( >hio and Michi-
gan, tell of stages of temporary halt or re-advance interrupting the general reces-
sion of the ice. During the greater part of the second or last I rlacial epoch, through
the time of general growth of the ice-sheet, while it was performing most of its
work of erosion and transportation of the drift, with the incorporation of a large
volume of detritus in the lower portion of the slowly moving ice, the only deposits
which it made were the subglacial till, or ground moraine, and scanty stratified
drift in subglacial water-courses. Outside the glacial boundary during the same
time beds of gravel, sand, clay and silt were laid down in the avenues of drainage
from the ice-sheet by the streams of its scanty melting beneath throughout the
whole year, produced by the heat of friction and the slight access of heat from the
earth's interior, and of its plentiful melting above, near its edge, by the sun's heat
and by frequent rains each summer. But during the time of departure of this ice-
sheet, which is known as the Ohamplain epoch, very abundant deposition of the
drift that had been inclosed within the ice took place, partly as till or unmodified
glacial drift, and partly as stratified or modified drift, transported, assorted and
laid down by currents of water. Professor James D. Dana * first directed the atten-
tion of glacialists to this rapid formation of diverse drift accumulations of Cham-
plain age, and gave this name to the epoch from its fossiliferons marine beds
adjoining Lake Champlain, which had been described by Professor C. II. Hitch-
cock ;f and President T. C. ChamberlinJ has named the ice-held detritus " englacial
drift," this term being applicable to it wdiile it was inclosed and being borne for-
ward within the ice, from which during the final melting it was deposited in many
forms, as the upper till, perched blocks, kames, osars or eskers, valley drift, and
loess. Besides these deposits derived from the englacial drift when the retreat of
the ice set it free, the terminal moraines were formed chiefly or wholly from it
during stages of glacial growth and advance; and the drumlins and other masses
of subglacial till were also made mainly by gradual additions of material that had
been englacial.

Nearly everywhere throughout the drift-covered areas glacial erosion has re-
moved all the preglacial residuary clay which more or less mantled the entire
country. This product of the preglacial denudation, and the gravel and finer
alluvial detritus of valleys, were plowed up by the ice-sheet and carried forward
in the direction of its motion; and portions gathered throughout great distances
along the path of the glacial current were mingled and thoroughly kneaded to-
gether. Occasional bowlders and rock masses were also supplied on the higher
lands by the irregular action of subaerial erosion and weathering before the ice
age, ready to he borne along and deposited in the glacial drift. Bui the ice-sheet
Commonly did more than to remove the loose material before existing, as is shown
by rock surfaces embossed, planed and striated by glacial erosion. In general, far
t he greater part of the drift was thus worn off, and most of its how iders were torn
and plucked away, from the rock floor over which the ice-sheet moved, grinding

•Am. Jour. 8ci., :;<! Beries, vol. v, 1st.:, pp. 198 212, and numerous papers in vols. \. \ii. win,
xxiv, Kxvi, and sxvii, L875-1884. Manual of Geology, firs! ed., 1802, p, ">I7 : third ed., 1880, p. 543.
; Gtoolog] of Vermont, vol. i. 1861, pp. L56 i > ,t .
; I . 8. Geol. Survey, Third Annual Report, for l881-'82, p, 297.

136 PROCEEDINGS OF WASHINGTON MEETING.

it with the drift material contained in its basal portion under the weight of thou-
sands of feet <>f ice. The large proportion of limestone present in the sand and
finely powdered rock of the drift in regions of limestone formations demonstrates,
as Chamberlinhas shown, that the drift was chiefly derived from glacial wearing
of the bed-rocks* It should be added, however, that the depth of the glacial ero-
sion was probably nowhere so great as to change the principal and grander topo-
graphic features of the preglacial contour. The most important influence of glacial
action upon the topography was usually the removal or partial wearing away of
comparatively small projecting knobs and the filling up of depressions and valleys.
bringing the surface to a more uniform contour than before the ice age.

If the rocks underlying the drift have been so universally glaciated, losing their
preglacial mantle of loose superficial deposits and further suffering almost every-
where much abrasion by the ice-sheet, it is evident that at some time between the
beginning and the end of the glacial period every part, even every square rod.
with rare exceptions, lias been subjected to grinding and rasping by the ice and
its enclosed drift. The thickest drift deposits when removed are found to have
rested on firm and sound rock, which bears no trace of preglacial weathering, but
is planed and striated by ice-wearing. We therefore must conclude that earlier or
later all of the drift has been plowed up and borne forward within the ice, or
pushed and dragged along beneath it, strongly held in the grasp of the bottom of
the ice. Any mode of action which seems consistent with the observed glacial
erosion of the rock floor would require intermingled ice and drift to lie swept
over it during some part of the glacial period. All the drift therefore has been at
some time essentially englacial, being transported while embedded in the ice.

But the masses of till forming slopes upon higher hills of rock, sometimes on
their lee side, sheltered from the ice-current, but often on the stoss or exposed
side, and not rarely in both situations, then almost enveloping the rock hill, were
evidently deposited beneath the ice-sheet as subglacial till or ground moraine, and
afterward remained undisturbed in their present place while the ice-current con-
tinued to flow over them. Indeed, the position and character of these slopes of till
prove that they must have been gradually accumulated by the addition of drift
which had been englacial and became lodged on their surface. The massive
hills of till, round, oval, or elongated, which are called drumlins, have many
features analogous with the slopes of till just noticed, and like them are doubt-
less subglacial accumulations consisting similarly of drift that was formerly engla-
cial, amassed in these hills by gradual accretion. Lower tracts of till, also occu] ly-
ing the greater part of the drift-bearing area, show by their composition, hardness,
and obscure lamination that they were subglacial deposits.

Among further proofs of the accumulation of much of the till under the ice, as
its ground moraine, are bowlder pavements, where a surface of till has been evi-
dently planed and its bowlders striated by glacial erosion. Again, one portion of a
rock surface has been occasionally planed and striated by a glacial current moving
in a different direction from that which similarly eroded an adjacent portion of
the same ledge; and the two areas often have different slopes, their line of meet-
ing being a beveled edge. < me part of the rock has been protected from the later

*U. S. Geol. Survey, Third Annual Report, p. 312; and Sixth Annual Report, memoir by T. C
Chamberlin and R. D. Salisbury, " The Driftless Area of the upper Mississippi," pp. 241, 247, 255 ;
also Am. Jour. Sci., 3d series, vol. xxvii, 1884, p. 388. Compare" Composition of the Till or Bowlder-
clay," by W. o. Crosby, Proc. Boston Soc. of Nat. Hist., vol. sxv, 1890, pp. 115-140.

WARREN UPHAM — DISTRIBUTION OF ENGLACIAL DRIFT. 137

erosion by a thin covering of subglacial drift. In such cases the glacial deflection
lias probably oftener been due to changes in the boundary and slope- of the ice-
sheet, ami consequent deviation of its currents during its general recession and
departure, rather than to two distinct glacial epochs."' A third proof of subglacial
accumulation is the fluxion structure observable at certain planes in many till
deposits, indicating that a surface layer of the till was frozen in the bottom of the
ice and dragged along over the underlying principal mass, with a shearing move-
ment of particle upon particle.t In this way, apparently, the glacial wearing ami
striation of the bowlders and pebbles of the till was mostly done.

Without attempting to review the vicissitudes of the glacial period, its two prin-
cipal glacial epochs with their varying stages of ice advance and temporary
retreat, and the long interglacial epoch, we see that during the progress of the
period all the surface of the bed rock was glaciated, and all the drift material was
for some time englacial or at least was grasped and borne forward by the basal
portion of the ice-sheet. In its passage across hills and mountains it is easy to
understand that the ice, closing up in the lee of the rock highlands, tore from them
many fragments, bowlders of large and small size, and rasped off much fine drift,
to lie locked in the embrace of the ice as it flowed onward hundreds, or sometimes
even thousands, of feet above the1 surface of the lowlands; and even on many por-
tions of the nearly level expanses <>f the St. Lawrence and Mississippi basins
eddying convergent and divergent glacial currents doubtless conveyed more or
less of the drift upward from the land surface into the lower part of the ice. At
Length, when the second or latest ice-sheet attained its greatest extent and thick-
ness, much englacial drift was contained within its ma<s, mostly in its lowest 1,000
or 500 feet, and extensive deposits of subglacial till lay beneath it.

Deposition of the Esglacial Drift during the Departure of the Ece-sheet.

Turning our attention to the ( 'hamplaiu epoch, or time of departure of the latest
ice-sheet, let us inquire, as the themes of this paper, What was the manner of
deposition of the englacial drift during the final ice-melting? What inequalities
are observable in the distribution of the englacial portion of the till? Why is it
abundant on some tracts and scanty on others? How was the englacial drift re-
lated to the terminal moraines? Can we discover through determinations of the
volume of the englacial drift a probable estimate of the time occupied in the
accumulation of the moraines? In what forms was the englacial drift left by
the departing ice? How much was laid down directly by the ice, and how were
other parts modified and unevenly distributed through the assorting, transporting,
and depositing action of water in rivers, lakes, and the sea?

The recession of the Lce-sheet, when warm climatic conditions returned, was by
rapid melting upon a considerable breadth, probably 100 to 200 miles or more of its
border, which was thus gradually pushed back across all (he drift-bearing area.
During the entire summer ami much of the spring and autumn of each year the
superficial melting or ablation of the ice produced many rills, brooks, and rivers.
Hydrographic basins were thus formed on the ice surface, resembling those of a

♦ Warren Upham, Geology of Minnesota, vol. i 1884, pp. 505, 549. T. <'. Chamberlin, "The Rock
Scorings of the Great ice invasions," I'. S. Geol. Survey, Seventh annual report, for l885-'86, pp.
200-207.

fHugh Uill.T. Reporl of the Fifty-fourth i ting of the Rritish Issoc. for the Idi ol 9i ii qci

Montreal, 1884, pp. 720, 721.

Will I'.i i i o,,,i . 9oc. Am., Vol . ::, 1891.

138 PROCEEDINGS OF WASHINGTON MEETING.

belt of country along a sea coast : but the glacial rivers and their large and small
branches had much steeper gradients than those of the present river systems on
the land surface, and often or generally they Unwed in deep ice- walled channels,
more like canons than ordinary river valleys. In the stages of growth and culmi-
nation of the ice-sheet it had possessed a nearly level surface of neve or accumu-
lating snow, mainly unflecked by any stone fragment or other drift material, or
even dust ; but when the final melting had dissolved away its upper portion, the
englacial drift begin to be exposed upon the surface, and at last on many areas the
ice doubtless became buried and concealed by this deposit, as was supposed by
Professor X. H. Winchell many years ago* and as was found by Mr. I. C. Russell
last year in his exploration of Malaspina glacier, at the foot of the Mount Si.
Elias range.f The completion of the ice-melting allowed much of the englacial
drift to fall loosely as an unstratilied deposit, called the upper till, on whatever sur-
face was beneath the ice. whether around moraine, oi other subglacial drift, or the
bed rocks. Previous to this, while the glacial melting was in progress, other large
portions of the englacial drift were washed away by the superglacial drainage and
deposited in beds of gravel, sand, clay, and silt, partly in the ice-walled channels
of the glacial rivers, but mainly beyond the ice-margin. The various formations
thus derived from the englacial drift will be more fully noticed in a later part of
this essay ; and our consideration is here directed especially to the process of disso-
lution^ the ice, releasing the drift which it had held.

Conditions analogous respectively with the growth and maximum extension of
the Pleistocene ice-sheets, and with their wane and departure, have been lately
made known to us in the case of ice-sheets now existing. The stage of growth or
ice accumulation is represented by the inland ice of Greenland, explored by Nor-
denskiold, Peary, and Nansen; and the stage of glacial recession, attended by
deposition of the englacial drift on the wasting ice surface and afterward on the
land beneath, is illustrated by the Malaspina glacier, as before noticed. The ex-
plorers of the Greenland ice-sheet describe its surface, excepting near the border,
as a vast expanse of neve, with no nunatak or peak rising above it, and with no
superficial drift. The line, gray powder which occurs somewhat plentifully on the
western portion of this ice«gheet, called by Nordenskiold " kryoconite," and believed
by him to he cosmic dust, but which Hoist i has regarded as a loess-like part of
the englacial drift, brought upward through the ice to its surface, appears instead
to be dust blown from a mountainous belt of land forming the western coast. On
the eastern side of Greenland, where Nansen's ascent upon the ice was made from a
part of the shore having little bare land, no noticeable quantity of this dust was
founds Xansen, in his expedition across the ice between latitude <>4° 10/ and lati-
tude *>4° 45', where its width is about 275 miles, encountered no streams of water
nor any water-courses at distances exceeding 20 miles inside the ice boundary ; and
he particularly remarks the absence of moraine d6hris or erratic blocks even on the
outer portions of the ice-sheet, excepting for a distance of " no more than a hun-
dred yards from the extreme edge."|| But a very remarkable contrast to all this

*Geol. Survey of Minnesota, First annual report, for 1872, ]» 62

f'An Expedition u> Mount St. Elias. Alaska," Nat Geogr. Magazine, vol. in. 1891, pp. 53-203.
X " Dr. N. O. Hoist's Studies in Glacial Geology," a review by Josua Lindahl, Am. Naturalist, vol.
xxii, July, 1888, pp. 594-598.
§F. Nansen, Tin- First Crossing of Greenland, vol. i. p. 483; vol. ii. p. 179.
|| Ibid., vol. ii, p. 479.

WARREN UPHAM — DISTRIBUTION OF ENGLACIAL DRIFT. 139

is afforded by the Malaspina glacier, with its drift-covered tracts occupying a width
of about five miles on its seaward border, bearing flowering plants and even forest
trees ; and by the large rivers of t lie associated alpine glaciers, one of which emerges
from an ice-tunnel, flows for about Id miles in a channel open to the sunlight,
walled by ice and having ice beneath it, and then enters the mouth of another
tunnel and disappears*

Though the ice-sheet of Greenland has formerly been more extended and deeper
than now. as is shown by glaciation of the rock surface high up on the sides of the
fjords, it has probably during several centuries been on the increase. There van be
little doubt that the climate at present is prevailingly colder than during the
prosperous period of the Norse colonies, between 900 and 500 years ago. By its
increasing accumulation, therefore, we may account for the contrast between the
Greenland ice, which has so little englacial and superglacial drift even near its
edge, and the partially drift-buried Malaspina -lacier in Alaska ; for there, accord-
in- to Russell, the ice has probably been on the wane during the past 500 or 1,000
years and at present is somewhat rapidly receding. Greenland is a picture of the
last glacial epoch at its culmination ; Alaska, of the Champlain epoch, of the final
melting of the ice-sheet and deposition of its englacial drift. The continuation of
these researches, now being prosecuted by Robert E. Peary and by Russell,
may be expected, therefore, to bring much further light on the history of North
America and Europe in the Pleistocene period.

Tracts of abundant Englacial Drift.

New England.— In Maine the maximum depth of the till is stated by Professor
( ieorge H. Stone to be about 100 feet. Over the areas of clay slates he doubts that
its average depth is greater than ten feet, but in some granitic regions it appears
to average 50 or perhaps even 70 feet in thickness. The average over the whole.
of Maine is estimated by Stone to he probably between •'!(> and 50 feet. t A con-
siderable fraction of this, not less than a tenth and perhaps as much as a fifth,
must have been enclosed in the ice at the time of its final melting; for the abun-
dant osars, kames, valley drift, marine clays, and deltas of sand and gravel, which
tins author has so well described.;: were derived by water transportation from
the englacial drift, and doubtless much besides remained to be dropped on the
surface as the upper part of the till.

In New Hampshire, which includes the most mountainous portion of New
England, after several years of work on the state geological survey, I estimated
the average thickness of the part of the till finally supplied from englacial drift to
be between three and four feet, this being the mean of sixty carefully observed

sections; and the modified drift, which was also englacial, has nearly the same

volume. The whole of the englacial drift in this state was therefore approx-
imately equal to a sheet seven feel thick.? To this we must probablyadd 1- or 15
feet for the mean depth of subglacial deposits of till (which I now think that I
then underestimated I, gh ing aboul •_'<» feel in total for the average thickness of all
the d rift, [n the White mountains and in very hilly districts the amount of drifl
is usually less than the average, many areas being mainly hair rock ; hut in a few

*" An Expedition to Mount St Elias," pp LOO-112,185 I
; Proceedings of the Portland Society oi Natural History, Nov. 21, 1881
! Am. Jour, s.i., :;,| series, \>>l xl. L890. pp. 122 l 1 1.
I ■ ology of N. II., \..l. ni, ^7s, pp, -Jiil, 292.

140 PROCEEDINGS OF WASHINGTON MEETING.

townships near the coast it is more, attaining there an average of 30 or 40 feet.
The distribution of the englacial drift, so far as can be judged by the derivative
stratified beds, was somewhat uniform throughout this state, while the subglacial
accumulations are very unequal and are wanting on perhaps half of its area.

Dr. Edward Hitchcock estimated the maximum thickness of the drift in Massa-
chusetts, excepting the heavily drift-covered southeastern counties of Plymouth
and Barnstable, to be 100 feet, and its average thickness 20 or 25 feet.* Some of
the drumlins of Boston harbor and of Scituate give evidence of rapid accumulation,
and show that the ice-sheet passing over them was plentifully charged with engla-
cial drift which lodged on their surfaces ; hut neither there nor elsewhere have I
been able to determine that extraordinary amounts of ice-held detritus were de-
posited as superglacial or upper till. The mean depth of this deposit is probably
about the same as in New Hampshire, and its averages in different districts may
range from one or two feet to live or perhaps ten feet. Besides, there is much
modified drift spread along the river valleys and on lowlands, becoming most con-
spicuous southeastward, near the terminal moraines, where great thicknesses of
gravel and sand, washed from the departing ice-sheet, form extensive tracts, in-
cluding the fore-arm of Cape Cod.

Vermont, Connecticut, and Rhode Island agree nearly with the foregoing as to
the amount and characters of the drift. For the whole of New England its volume
is probably equal to a uniform sheet 30 or 40 feet thick, of which about a quarter
part was englacial at the time of final melting of the ice.

\i "■ York. — No other state surpasses New York in contrasts of topography and
in diverse development and distribution of«rhe drift. From Syracuse westward
along a distance of 00 miles the traveler on the New York Central railroad sees a
profusion of drumlins 50 to 150 feet in height, trending from north to south in
parallelism with the glaciation of the region and with the neighboring "finger"
lakes, which occupy fjord-like valleys on the south. Through this part of the state
and generally across its southern half, the drift has a greater average thickness
than in New England. Northward, between Vermont and Lake Ontario, the
Adirondack mountains and some lowland areas have tracts of very scanty drift,
while other continuous tracts are abundantly drift-covered. That a large amount
of drift was here enclosed within the ice and set free by its departure is shown by
the portions supplied from it to form such extensive -ravel and sand plains as
stretch from Coeymans northward to Albany and Schenectady, again from near
Rome across many miles northwestward, and through Clay and Schroeppel, west of
Oneida lake, and from the great bend of Black river northeastward in Wilna.

Minnesota. — A very great depth of drift, averaging loo to 150 feet, is spread over
all the western half or two-thirds of Minnesota ; but in the northeastern part of
this state a large area was swept bare by the eroding ice-sheet. During the first
year of my work on the geological survey of Minnesota, in examination of twenty-
two counties lying in its central and western portions, I obtained notes of the order,
thickness, and characters of the drift deposits passed through by about 600 wells.
Nearly half of these found beneath the englacial upper till a much harder lower
till, which was compacted by the pressure of the ice during its subglacial deposition.
The extremes in thickness of the englacial till were ."> to ."i feet and 40 feet. t Later

♦Geology of Mass., 1841, p. 365.

t Geological Survey of Minnesota, Eighth annual report, for L879, pp. 109-117.

VVAKKEN I 1'IIA.M — DISTRIBUTION OF ENGLACIAL DRIFT. 14J

examinations of other counties in the eastern and the southwestern parts of the
state gave three localities where the thickness of the englacial drift deposited at

the time <il' linal recession of the latesl ice-sheel is very clearly displayed by its
stratigraphic relations and by the erosion of water-courses. They can be only
briefly noticed here, and the final reports of this survey may be referred to for
detailed descriptions of the facts observed, with the full interpretation of their
significance. The must eastern of these Idealities is a plain of englacial till LO to 20
feet thick, overlying sand ami gravel which were deposited from a previously
melted ice-sheet, upon a width of five miles and length of probably fifteen miles in
Chisago and Pine counties.* Another similar flat tract of till, 16 to is feet thick,
overlies earlier modified drift near New ITIm.f The third and must interesting
group of observations was at lakes Benton, Shaokatan, and Hendricks, adjacent to
the outermost or Altamont moraine on the < !oteau des Prairies. These lakes lie in
water-courses which were channelled in the superglacial drift and continue through
the moraine. A thickness of al least 40 feet of englacial and afterward superglacial
drift is thus proved to have existed close to the ice boundary, where it was form-
ing massive morainic accumulations.:!:

Manitoba. — The great belt of modified drift which extends from St. Paul and
Minneapolis north-northwest ward by the sources of the Mississippi and Red rivers
to the Lake of the Woods and to Bird hill in Manitoba, seven miles northeast of
Winnipeg, proves that much drift was contained in the ice-sheet along that dis-
tance of 400 miles. Toward this belt glacial currents converged from the northeast
and from the west and northwest, bringing doubtless more englacial drift than its
average in other parts of the ice-sheet: lis amount at the osar called Bird hill
appears to have been aboul 40 feet.?

Another area to which much englacial drift was broughl by convergenl ice cur-
rents is the region of Riding and Duck mountains and the upper part of the Assini-
boine basin, as is shown by the immense supply of modified drift contributed by
the retreating ice to the Lake Agassiz delta of the Assiniboine river. Probably
more than ten cubic miles of gravel and sand, besides much liner silt and clay, were
there washed away from the melting ice surface and swept into this glacial Iake.[|

Ti: \i is or s< avi v Engl \< i \ i. I >i;i it.

X< w England. — As an example of tracts know n to have verj thin englacial drift

from their being well nigh destitute of any superficial deposits and consisting in
large part or almost wholly of bare rock, we may cite the bell of very rocky, broken
country a few miles north of Boston, from Salem, Marhlehead and Lynn this
tract, occupied by Archean granite, felsitesand diorite, extends westward to Stone-

ham and Winchester, its western pari being known as the Middlesex fells. The
action of the ice-sheet here seems to have been to sweep away whatever materials
it could gather, leaving drift deposits only where they became ensconced in hol-
low-, and are thus shown to have been subglacial.

* i Minn., vol ii. 1888, pp. U3-417.

fGeologyof Minn . o.l. i. 1884, pp. 581, 582.

Ibid I "I. i. pp. IS03 604,
g" Glacial Lake \ ■_■ ■ iz in Manitoba," (feol. Sitrve, ta, Annual Report, new series, vol. iv,

foi I--- ->. pp 16 12E.

/ 90E; Bull. Geol. Soc. lm., vol. 2, 1890, pp. 272-274,

142 PROCEEDINGS OF WASHINGTON MEETING.

New York. — Remarkable scantiness of drift characterizes parts of Henderson,
Hounsfield, Brownville, Lyme, Clayton and other townships of Jefferson county,
New York, bordering the eastern end i>i' Lake Ontario, seen by me last autumn
during surveys with Mr. < '<. K. < rilbert on the beaches of the glacial lake Ontario
or Iroquois. Tins tract differs widely in topography and geology from that cited
in Massachusetts; for it has a flat, very gently inclined surface, and consists of
nearly horizontal beds of the Trenton limestone. The roads often run long dis-
tances on the nearly level solid rock; and the soil of the fields, though supplying
good pasturage and cultivated crops, is only a few inches or in its deepest parts a
few feet thick. This almost continuous but very thin mantle of drift appears to
have been chiefly englacial, the bottom of the ice having rested on the rock.
Within a distance of a few miles eastward, however, the drift has a considerable
depth, and is here and there heaped in beautiful oval drumlins, which rise 50 to
100 feet or more above their base.

Minnesota. — A much larger area having surprisingly scanty drift deposits lies
north and east of Vermilion lake. Minnesota, consisting of Archean schists with
very hilly contour and plentiful lakes in rock basins. So little drift is found here,
and so extensive are the exposures of hare rock, that Professor X. H. Winchell has
called it a driftless region;* but it has been everywhere glaciated, and many de-
posits of subglacial till must he lodged in the depressions between hills and ridges.
The whole volume of drift in this region is very little, in comparison with other
thickly drift-covered portions of this and adjoining states, and of this little the
proportion which was englacial is small indeed.

North of Rainy Lake ami the Lake of theWoods. — Continuing northward and north-
westward, this area of scanty drift comprises a great extent of country crossed by
the Canadian Pacific railway between Port Arthur and the Whiternouth river. Its
southwestern limit runs from Vermilion and Net lakes northward across Rainy
lake and northwestward across the northern, island-dotted portion of the Lake of

the Woods.

Dr. George M.Dawsonj and Mr. A. C. Lawsonj have referred the gravel and
sand beds which are widely spread southwest of this line, about the southern part
of the Lake of the Woods and along Rainy riverto the mouth of Rainy lake, within
the area of the glacial Lake Agassiz, to lacustrine action. This explanation, how-
ever, is inconsistent with the restriction of these deposits to a small part of the area
of this glacial lake, and with their extension far southward (to the head waters
of the Mississippi and to St. Paul, as before noted), beyond the limit of the lake
and upon a district that rises in part considerably above it. Instead, the distribu-
tion and character of these modified drift beds indicate that they were derived
directly from the englacial drift which abounded in the ice-sheet upon this belt.
On a large adjoining region next to the northeast, however, the drift is so scanty
that much of the surface is bare rock, strikingly contrasting with the country
SOUthwestward, which across distances of 100 to 200 miles is wholly drift without
a single rock outcrop.

i ■■ ology of Minn., vol. i. pp. 117, 131 ; Minn. Horticultural Society, Annual Report for 1884, p. 398.

t Report on the Geology and Resources of the region in the vicinity of the Forty-ninth Parallel.
1875, pp. 203-218.

JGeol. Survey of Canada, Ann nil Report, new ~.-i ie<. vol. i. for 1885, pp. 131 and 139CC; vol. iii. for
1887-88, pp, 17!-17t, V.

WARREN UPHAM — DISTRIBUTION OF ENGLACIAL DRIFT. 143

Relationship of the Englacial Drift to the Terminal Moraines.

The irregular distribution of the englacial drift, thus abundant and scanty on
adjacent areas, was not apparently dependent on the character of the underlying
formations, nor on the altitude or configuration of the land, but rather on the
course, intensity, and limits of the great currents of glacial outflow from the central
part of the ice-sheet. There is consequently a marked relationship between the
inequality of distribution of this ice-enclosed material and the development of the
terminal moraines or marginal accumulations pushed out by these glacial currents
along the irregularly lobate boundaries of the ice during its maximum stage and at
halts in its recession and departure. The axial portion of each ice-lobe was more
an area of glacial erosion and less of deposition than its borders; and where the
glacial erosion was most severe and prolonged until the departure of the ice the
amount of both subglacial and englacial drift is small, the product of erosion being
carried to the outer portions of the ice-lobe or district of glacial outflow and there
deposited. On this principle we account readily for the deficiency of drift in
the extensive region north of the Lake of the Woods, Rainy lake, and Vermilion
lake, where the ice pushed strongly southwestward ; and for the abundance of drift,
much of it modified and therefore known to have been englacial, upon the adjacent
belt described between St. Paul and Winnipeg, where the ice currents from the
northeast and northwest were pushed together. The same principle also explains
the scantiness of drift upon large portions of Labrador and of most arctic lands.
Powerful glacial erosion has removed their preglacial superficial detritus and much
of the solid rock, sweeping nearly all its drift beyond the coast line.

Even where small tracts of very scanty drift occur, with contiguous tracts
deeply drift-covered, as the instances cited in Massachusetts and New York, this
explanation probably still holds good, but applies to the latest movements of the
ice-sheet on these areas. It has seemed to me probable that the border of the ice
during its recession, melted by the returning warmer climate, had generally a more
Steeply sloping surface than in its time of greatest extent, and that in consequence
the rate of motion of the outer part of the ice-sheet was even increased during its
final melting. This would account for exceptional erosion and scantiness of drift,
either subglacial or englacial, on such limited tracts, and for its being thickly
amassed, often in drumlins, not far distant. Whether we consider the inequalities
of the drift distribution upon the larger tracts where they were due to the grand
movements of outflow of the continental ice-sheet, or upon the smaller tracts
where the irregularities of erosion and deposition seem attributable to minor
movements during the departure of the ice, it is clearly indicated that the deposi-
tion of the drift took place largely beneath the ice and near its boundaries. For
example, \ find reasons for believing that the drumlins near Boston were chiefly
accumulated during the departure of the ice at distances of only a few miles inside
its retreating edge* At the same time, probably, the tract of very scanty drift
close to the north was undergoing severe erosion.

Impressive as are the more massive portions of the belts of marginal morainic
drift, they musl have been far larger if the ice had home most of its englacial drift
quite to its margin, instead of depositing it as subglacial till beneath its compara-
tively thin border. Professor N. S. Shaler estimates the terminal moraine on the
northwest pari of Marthas Vineyard to be on the average L50 feel thick, its volume

♦ Proceedings Boston Society of Nnturnl History, vol. sxiv, 1889, pp, 228 242.

144 PROCEEDINGS OF WASHINGTON MEETING.

on an area ten miles long and one and a half miles wide being equal to that <>f
Monadnock mountain in New Hampshire.* In the deep north to south valleys of
southern New York the morainic deposits; according to ( lhamherlin, have probably
sometimes a depth of 500 or 600 feet.t The Leaf hills, which are the most conspicu-
ous moraine of Minnesota, rise LOO to 350 feet above the surrounding drift-covered
country. In Manitoba the moraine that forms the western part of the Tiger hills and
the Brandon and Arrow hills is piled up 100 to 250 feet at its highest points; and
equally prominent morainic hills, according to Mr. J. B. Tyrrell, lie on the top of
Duck mountain, rising to altitudes of 2,500 to 2,700 feet above the sea. j

All these great moraines, and the less conspicuous portions of the same belts con-
sisting of small hills or having only a moderately rolling contour not more than 20
to 50 feet ahove the country on either side, were accumulated from englacial drift.
Let us consider, therefore, the probable rate of motion of the ice and the amount
of its englacial drift, to ohtain therefrom some estimate of the length of time
occupied in the formation of the moraines. The How of the glaciers of the Alps,
as is well known, varies from one to two or three feet per day: hut the daily
advance of the central parts of the thick and wide glaciers of Greenland and
Alaska, where they enter the sea. is found to be from 30 to 100 feet. Doubtless the
continental ice-sheet moved faster than the Swiss glaciers ; hut the waste from its
border by melting must evidently have been far less than the discharge of ice from
arctic glaciers that terminate in the sea and arc broken into bergs and floated
away. If the average amount of englacial drift supplied by the ice-sheet where its
moraines are largest he assumed equal to a thickness of twenty feet or even ten or
five feet, thus supposing half or a much larger part of the whole volume of ice-held
drift to he very near the ground where its onward movement was retarded by
friction and it was prevented from contributing very rapidly to the marginal mo-
raine, and if we assume a rate of motion in the higher part of the ice somewhat
greater than that of Alpine glaciers, a short computation will show that a few
decades of years, or at the longest no more than a century, would suffice for the
accumulation of even the largest of our terminal moraine-.

Forms in which the Englacial Drift was deposited.

Forms of Drift. — Four classes of drift may he discriminated, differing in their
place and manner of deposition, namely: (] i Subglacial till, which was accumu-
lated beneath the ice-sheet ; (2) Marginal till, constituting generally the principal
mas- of the terminal moraines ; (3) Englacial till, which, during the departure of
the ice. became superglacial and finally was dropped on the land when the glacial
melting was completed: and (4) Modified drift, comprising the glacial sediments
that were derived directly from the ice-sheet, hut were assorted, transported, and
deposited by water. The last-named class occurs in many diverse forms. Some
of its beds were subglacial and others marginal, a- to their place of deposition ; hut
far the greater part of the modified drift was englacial at the time of the final
melting, and was then washed away from the ice surface by the streams of its abla-
tion and by rain-.

Our enumeration of the various forms in .which the englacial drift was deposited
during the Champlain epoch, that is, the time when the ice-sheet was melted away,

*U. - Geol Survey, Seventh annual report, for l885-'86, p. ■■\±
tU. S. Geol. Survey, Third annual report, for :881-'82, pp. 351-358.
} Am. I ieologist, vol. viii. p. 22, July, 1891,

WARREN fl'ITAM — DISTRIBUTION OF ENGLACIAL DRIFT. 145

may be somewhat brief, the chief point to be brought into view being the inequality
of its distribution.

Englacial Till. — The chief characters of the englacial upper portion of the till, as
compared with the subglacial lower portion, are its looser texture ; its more plenti-
ful and larger bowlders ; the prevailingly angular or subangular shapes of its bowl-
ders ami smaller rock fragments, whereas they are mostly worn smooth and planed
by glaciation in the lower till ; and the usually more gravelly and sandy and less
clayey composition of the englacial till, owing to the washing away of much of its
finer material by the superglacial drainage. To these originally inherent characters
we must add the very noticeable postglacial peroxidation and hydration of the
-mall ingredient of iron, giving to the upper part of the till a yellowish-gray color,
while the lower part, holding the iron in protoxide combinations and as pyrite,
has a darker and bluish color. This change has generally extended through the
englacial till, stopping at the more impervious subglacial deposit. Between the
two there is also frequently a layer of subglacial stratified gravel and sand from a
few inches to several feet thick.

The proportion of the englacial drift dropped as till and that borne away by
streams in New Hampshire appear to he approximately equal ; and probably it is
also true for most other parts of our drift-bearing area that about half of the en-
glacial material became till and half modified drift.

The extremes of thickness of the englacial till in Xew Hampshire, so far as ob-
served, are one foot and seventeen feet. Its inequality of distribution in other
states appears to range, as before described, from almost nothing or only a few feet
for its minima to about forty feet for its maxima near massive terminal moraines
and where great currents of the ice-sheet converged.

Perched Blocks. — Bowlders and all rock fragments and other drift enclosed in the
Lee at a considerable height above the ground were borne forward without attrition.
This higher part of the englacial drift supplied most of the material forming the
terminal moraines, which therefore have a remarkable profusion of bowlders and
angular gravel. When the ice-sheet was finally melted its enclosed bowlders were
dropped, and they now lie frequently as conspicuous objects on both the tower and
higher parts of the land. Perched on the sides and tops of hills and mountains,
they at first suggest transportation and stranding by icebergs or floe-ice. Some
of these blocks are very huge and have 1 raveled far, as the "Three Maidens" at
the lied Pipestone quarry in Minnesota, where a single immense bowlder has
fallen into three pieces thai measure each about 20 feet in length and 12 feet in
height, besides several smaller masses* Two perched blocks, measuring respect-
ively 42 by 40 by 20 feet and 40 by 30 by 22 feet, found by Dr. G. M. Dawson on
the eastern font-slope of the Rocky mountains about 3,300 feet above the sea, ami
others in the same region up to 5,280 feet, were derived from the Axchean area
some 700 miles distant/! But the longest distance of transportation of drift within
the ice-sheet know n on this continent is fully 1,000 miles, from the eastern side of
Hudson bay, where il narrows into .lames bay. to the southwest and south into
southern Minnesota.

Karnes. — McGee \ ami Chamberlin^ have judiciously proposed the restriction of

*( reologj Of M il Ol. i- I v" I, 1'. 540.

FQeol. Survey of Canada, Report of Progress for L882-'83-'84, pp.147 1 19C.

| Reporl of the International Geological gress, 9 ud session, B 1881, p. 621.

-. 1 1 Survi y, Third annnal report, for l881-'82, p. 299; Am. Jour. Sei., :;.i series, vol. \\\ ii

X I \ I'.i 1 1 S01 V.i . \ 01

146 PROCEEDINGS OF WASHINGTON MEETING.

the term " kames " to the knolls, hillocks, and short ridges of sand and gravel which
were heaped at the months of glacial brooks and rivers where they left their ice-
walled channels and were spread out more widely, thereby losing their velocity
and carrying power, on the adjoining land surface. These deposits are frequent on
many portions of the general drift sheet, but they are most fully developed in con-
nection with the terminal moraines.

Osars or Eskers. — Prolonged ridges of gravel and sand, or in some tracts of finer
silt, narrow anil bordered by steep slopes on each side, called osars or eskers, owe
their form to deposition in the channels of glacial rivers, walled by ice, but
commonly open to the sky.* These peculiar ridges have a great development in
Sweden and Ireland, whence their names come, and in Maine, where series extend-
ing 100 to 150 miles have been described by Professor George H. Stone.t They are
well exhibited also in the valleys of the Merrimack and Connecticut rivers and
elsewhere in New England, but are less frequent on the nearly flat expanses of the
upper St. Lawrence and Mississippi basins. Associated plains of gravel and sandj
terminating in steep escarpments, which descend to adjacent lower land, were
deposited in broad embayments of the waning ice-border.

Valley Drift. — In the valleys and on the lowlands uncovered by the departing
ice extensive flood-plains of gravel, sand, and clay were spread by the waters of
the glacial melting and the accompanying abundant rains. These deposits slope
with the present streams, but often somewhat more rapidly ; and they continue in
large valleys to the sea or to the areas of lakes that were pent up against the reced-
ing ice-sheet, and there form deltas and, farther offshore, sediments. Since the
departure of the ice, river erosion has carved the valley drift into terraces, and the
streams now flow far below their levels of the Champlain epoch.

Loess. — The finest portion of the valley drift, especially where it contains some
glacially comminuted rock flour from calcareous formations, is called loess. In the
Mississippi and Missouri valleys and on the Rhine this deposit is clearly in large
part of glacial origin, being directly supplied from englacial drift ; but very similar
fluvial beds are now being formed by the Nile, and were formerly spread in great
thickness by the rivers of China, where the origin of the silt is referable wholly or
chiefly to subaerial denudation

Deltas. — The marine delta deposits of the rivers of Maine, and the marine claya
which are spread extensively along the Maine seaboard to a height about 230 feet
above the present sea level, were chiefly derived, according to Stone, from engla-
cial drift. Likewise, the great deltas brought by the Assiniboine, Pembina, Shey-
enne, and other rivers into the glacial Lake Agassiz are largely modified drift from
the ice-sheet and in less amount alluvium from ordinary river erosion. South of
Maine much modified drift was borne into the ocean by the Merrimack, Connecti-
cut, Hudson, and other rivers, while their portion of the coast was more elevated
than now, so that their marine sediments are still beneath the sea.

All these modified drift deposits are distributed in accordance with the laws of
aqueous sedimentation. The kames and eskers, having been laid down in the ice-
walled mouths and channels of glacial rivers, now lie as hillocks and ridges, which

♦Proceedings Boston Society of Natural History, vol. xxv, 1891, pp. 23.S-242.

t Proceedings Boston Society of Natural History, vol. xx, 1880, pp. 130-469, with map; Proc. Am.
Assoc, for Adv. of Science, vol. xxix, for lsso, pp. 510-519, with map. Am. Jour. Sei., 3d series, vol.
xl, 1890, pp. 122-141.

WARREN UPHAM DISTRIBUTION OF ENGLACIAL DRIFT. 147

find their only explanation, as to form and origin, in the drainage system of a
melting sheet of land-ice. The greater part of the modified drift, however, was
laid down outside the receding ice-margin, and occupies the avenues of drainage
from the ice to the sea ; and where the ice-border lay in or near the sea, or a great
lake, deltas of gravel and sand were formed and the finer silt was distributed more
widely and thinly by coastal currents.

Influence of adjoining Lakes or tiie Sea.

From Nantucket and ( 'ape Cod northeastward the ice-sheet at its greatest extent
and during a considerable part of its time of recession terminated in the ocean.
In the interior of the continent, too, it was bounded during its recession by vast
glacial lakes, filling the basins that are now partly occupied by the great lakes of
the St. Lawrence, Nelson, and Mackenzie rivers. During six summers of field-work
in examination of the shore lines, deltas, and bed of Lake Agassiz, the largest of
these glacial lakes, I have carefully studied the effects attributable to the influence
of this lake in the deposition of the drift, comparing its area, the valley of the Red
river of the North, with other portions of Minnesota, South Dakota, North Dakota,
and Manitoba, which were land surfaces during the departure of the ice. Other
glacial lakes of smaller size in these states and Canadian province have also come
under my observation, besides portions of the drift deposited in the glacial precur-
sors of the Laurentian lakes ; and on the Atlantic coast I have made a detailed
examination of the marine drift of southeastern New Hampshire. The more
southern parts of the New England seaboard which I have similarly examined, in-
cluding the coast from Boston to Plymouth, Cape Cod, Nantucket, Marthas Vine-
yard, the Elizabeth islands, Block island, and Long island, appear to me to have
stood at their present height or somewhat higher during the maximum extension
and the recession of the last ice-sheet.

Upon all the areas thus studied by me where the ice-sheet was bordered by great
lakes or the sea, tracts of stratified sediments, as deltas of gravel, sand, and silt, and
somewhat more extensive deposits of finer silt and clay, are found ; and their dis-
tribution shows them to have been chiefly brought into these bodies of water by
rivers flowing down from the melting ice. But a huge portion of the englacial
drift, corresponding to that which elsewhere fell as wholly unstratitied till on land
areas, was received from the receding ice into these lakes or the sea with Little
change, being allowed to fall to their bottom only very slightly modified by water
action. Within the area of bake A.gassiz and the other associated glacial lakes very
extensive tracts, probably half or a larger part of their whole extent, have a surface
of till which differs from its characters on the adjoining tracts that were land dur-
ing the iee retreat in having usually slight traces of stratification within the five to
fifteen feel of the upper and englacial till, and in bavin-- a more smooth and even
contour.

Bowlders, gravel, sand, and clay are mingled in this englacial till in the same
proportions as on the country outside these glacial lakes. There was generally no
noteworthy transportation ofbowlders or other drifl by ice floes or bergs on these
lakes ; nor was the line clayey pari of the englacial drifl washed away in any note-
worthy amount from the submerged and melting and receding ice-margin by wave
action, which would have covered the i ill in fronl of the ice-sheel with beds of silt,
[nstead, the englacial an. I finally Buperglacial drifl that escaped the stream erosion

148 PROCEEDINGS OF WASHINGTON MEETING.

of the drainage from the glaeial melting sank through the water to the bottom as
the ice gradually withdrew, and exhibits essentially the same characters as on
areas that were land, excepting its usually obscure traces of stratification and its
smoother surface.

Remarks were made upon the paper by Robert Hay.
The following paper was read :

EFFECTS OF DROUGHT AND WINDS ON ALLUVIAL DEPOSITS IN NEW ENGLAND.

BY HOMER T. FULLER.

For twenty years or more I have been watching with much interest some slow
changes of the surface of terrace formations in the valleys of New England rivers.
The large predominance of granites, gneisses, and crystalline schists in northern
Xew England east of the Green mountains has brought it about that the material
ground up and deposited in these river valleys, both by glacial and river agencies,
is chiefly quartz sand. On these terraces vegetation must have been very slow in
getting a foothold. First, creeping vines, like the strawberry or low running black-
berry or shrubs of diminutive size, may have advanced under the shade of larger
shrubs and trees which bordered the water-courses ami which gradually, too, climbed
the slopes and occupied the plateaus. At all events, we know that these terraces in
the valleys of the southwestern part of the territory mentioned were once covered
with a magnificent growth of pine and elm and chestnut : that in the central region,
even on these sandy soils, the maple and poplar and sometimes even the hemlock
and beech thrived, and that farther northward the spruce grew everywhere. Nov .
however, portions of these terraced slopes are becoming absolutely desert, as bare
of any vegetation as are the tracts of the African desert westward from the meadows
of the Nile.

The object of this paper is to direct the attention of this Society first to the facts,
as illustrated specially by one or two localities which are typical, and secondly to
the causes as determined by long continued observation.

As might be presumed, the tracts most affected are above the reach of river over-
flow and where glacial erosion must have provided the material which was in the
epochs following more finely pulverized and then separated by running streams.
One of the best illustrations is presented in the valley of the southern branch of
Sugar river, a tributary of the Connecticut, in the towns of Lempster, Goshen, and
Newport, Xew Hampshire. This valley is a section of what in the later Glacial and
early Champlain epochs must, if I mistake not, have been first a continuous stream
of ice and then a broad river from almost under the shadow of Moosilauke moun-
tain, in Grafton county, to near the Massachusetts border, if not, indeed, through
to Connecticut. The proof is found in the continuous valley that extends nearly
from north to south throughout this extent, and which lies west of Monadnock, the
Snnapee range and Kearsarge, in Wilmot, and east of Grantham and Croydon
mountains and the high hills of Unity, Lempster, Alstead, and Surry ; and, secondly,
in the height of terrace formations above and near the sources of the several streams
which now drain the various sections of this longitudinal depression. In Lempster,
for example, these terraces are twenty to forty feet above the sources of Cold river,

II. T. FULLER — DENUDATION AND DEFLORATION. 149

which flows southward, and Sugar river, which flows northward, and are found yet
within a half mile of the glacial moraine which is the watershed between them.

These terraces were in the early part of the present century all clothed with
forests. Some of them have been cleared and all of them cultivated within forty
or fifty years. Later they were given up to pasturage, and in the course of fifteen
years after I began to notice that the rounded slopes of these sugardoaf lulls on the
southwestern sides began to lose their green, and bare sand appeared. Then the
sand began to drift, generally toward the southeast, until in some spots acres were
denuded of vegetation and other acres were covered three, four, and five feet in
depth by the drifted sand. The work of destruction has continued until consider-
able parts of large farms are now worthless. The pi lenomena are confined to grassed
lands, either mown or pastured. They cannot be caused by the action of water
chiefly, because the beginnings of these changes are neither in ravines nor on the
sides of ravines, unless, perchance, a slope is toward the south or southwest, but
on the swells of the slopes.

The process appears to be this: First, the pasture is fed oil' or the field mown
until the humus or organic matter in the soil, which is always thin, is exhausted or
nearly so. The roots of the herbage are feeble and shallow. By and by a dry
season occurs, and on the south-southwesterly slope, where the sun's rays strike
almost vertically in the hottest part of a summer day, the grass dries up root and
1 (ranch. The next spring these very spots lose more quickly than others the snow
as it melts under the sun. Then the winds that follow in the months of March and
April, generally in fair weather blowing from the Avest or northwest, cut out, as
they strike the surface at a very slight angle, the dry sand and transport it to the
nearest lower spot to the leeward. Sometimes the drift has gone across highways
or through double fences of open rails or boards ; sometimes, indeed, the sand has
blown over the higher crest of the ridge and been deposited on ground more elevated
than that whence it came. My observations of this denudation and defloration of
line silicious soils have covered the valleys of the Androscoggin ami >aco rivers in
.Maine and New Hampshire, of the Merrimack and Connecticut and their tributaries
in New Hampshire, Vermont, and Massachusetts. But I have noticed the begin-
nings, less marked, of the same kind of destruction of vegetation in southern New
York on the headwaters of the Alleghany river, and in northeastern Pennsylvania
on Oil creek, though these are comparatively newly cleared regions. For these
bared knolls one must look on the eastern or northern sides of valleys and for
the slopes thai dip a little west of south. The three causes, as I have already inti-
mated, are the shallowness or exhaustion of the soil, drought, and wind. I'nless
in some way counteracted, the "old fields" of the north may yet, if not in extent
yel iii desolation, vie with the "old fields " of the south. The only remedy is fer-
tilizing and sheltering the bared spots, planting trees to the windward, abandoning
grazing, and letting the forests again as of old occupy and reclaim and enrich in
nature'.- own way the areas which continued cropping lias exposed to waste by
drought and varied erosion.

150 PROCEEDINGS OF WASHINGTON MEETING.

The last paper was as follows :

A DEEP BORING IN THE PLEISTOCENE NEAR AKRON, OHIO.

BY E. W. CLAYPOLE.

The preglacial geography of the northern part of Ohio has been so largely ob-
scured by the mantle of glacial material deposited upon it that its restoration is
attended with much difficulty. That some communication existed whereby the
waters flowed into Lake Erie from a greater distance to the southward than is now
the case has long been believed. A communication between the Cuyahoga and
Tuscarawas rivers seemed to be rendered necessary by the physical geography of
the region. At present the watershed passes about three miles south of Akron;
but it is soon evident to the glaeialist, and indeed to the observer if intelligent,
though having no special knowledge of geology, that the great preglacial valleys
which cross the country cannot have come to a sudden end at the present water-
shed, but must have continued to some distance southward. It has been generally
assumed that this channel lay through the city of Akron, where is now a deep
valley apparently forming a connection between the valleys of the Tuscarawas and
the Cuyahoga. The depth of tins valley to rock has never been proved, but wells
have been sunk in the gravel which tills it to 150 feet or more without reaching
bottom* This gravel is the deposit of the retreating ice-sheet, and lies in great
quantity south of Akron between the two lobes of the glacier which covered this
part of the state. It is therefore postglacial in date.

Several circumstances, however, which cannot here be detailed combined to in-
duce the belief that this channel did not at anytime form a link of communication
between the valleys of the present < !uyahoga and Tuscarawas. The narrowness of
the channel in which the latter river now flows along part of its course is sufficient
proof that it is not very deep, though undoubtedly preglacial. Accordingly, it was
desirable to find some other way in which the water from the south could have
found its way to bake Erie through the Cuyahoga.

To the west of Akron, at the distance of about three miles, lies a wide swamp
leading south from the Cuyahoga to the Tuscarawas valley, and to this my atten-
tion was directed some years ago, but no data could be obtained concerning it ; all
indications were in favor of a buried channel of considerable depth through which
the long-sought passage might be found. During the winter of 1890, however, an
Akron firm determined to put down a deep well in search of brine. Fortunately
forthe geologist, they chose nearly the middle of the valley above mentioned. Sup-
posing that there would be some depth of soft material, the contractor obtained 100
feet of 8-inch pipe to be driven. A second lot followed, and a third, nor was it until
nearly 400 feet had been driven (389) that the rock was at length reached.

This result, so different from expectation, changed the views previously enter-
tained regarding the preglacial drainage of the district and revealed the true level
of connection between the two above-mentioned rivers. Evidently the southern
waters had come north, not through Akron, but through this newly revealed valley,
whose bottom five miles south of Akron was now found to lie on the present level
of Lake Erie. So deep a preglacial channel close to the watershed of the continent

*From one of these wells, at the depth of aboul 150 feel tip- sand-pump brought up with the
gravel a flint arrow-head.

E.W. CLAYPOLE — BORING IN THE PLEISTOCENE. 151

indicated a considerable southward extension of the system of drainage, the extent
of which is yet to be determined.

This preliminary note is not the occasion for further extension oft lie subject, but
it may be remarked in conclusion that the valley above described is not, as that
through Akron, filled with gravel, but with the same tine silt, mingled with some
sand, which was described in the author's tract upon the Cuyahoga valley* as fill-
ing the glacial " Lake Cuyahoga " and being the deposit of its icy waters. This silt
maintains a nearly flat surface, rising almost to the level of the watershed at Summit
lake.

This discovery has, moreover, enabled the author to ascertain more exactly than
was previously possible the outlet of this Lake Cuyahoga. Its waters extended
southward along the swamp above mentioned until they were confined between
the western wall of the preglacial valley and the moraine which gradually extended
westward, and so narrowed it that at present there is only room a few miles farther
southward for the exit of the present Tuscarawas, the canal, and the railways. This
overflow or " col " is only a few feet below the level of the summit, and t( > all appear-
ance the glacial lake that occupied it was nearly filled with this tine deposit during
the retreat of the ice.

This paper was discussed by Edward Orton and Frank Leverett.

The Society reassembled in general session.

The following resolutions, offered by C. R. Van Hise, were unanimously
adopted :

Resolved, That the Geological Society of America return sincere thanks :
First. To the officers of the Columbian University for their kindness
in tendering the use of their buildings to the Society.

Second. To the local committee, Mr. Bailey Willis and Dr. George P.
Merrill, who have, by their careful and painstaking preparations, con-
tributed so largely to the comfort of the members of the Society and to
the success of the Society's meetings.

It was also moved and voted that the thanks of the Society should be
conveyed to the foreign visitors for their presence at the meetings and
the papers which they had presented.

Acting President Gilbert then made some announcements relating to
the International Geological Congress, receptions, etc., and. after a few
appropriate remarks, declared the summer meeting of the Society ad-
journed.

*See "Thi Lake ^ge in Ohio' (E I llarke a Co., Cincinnati), for further details on this svtbji

The following Fellows were in attendance at the meeting

George F. Becker.

John ('. Branner.

Garland C. Broadhead.

Samuel Calvin.

Henry Donald Campbell.

T. C. Chamberlin.

J. H. Chapin.

Clarence Raymond ClAghorn.

William B. Clark.

Edward W. Claypole.

Theodore B. Comstock.

Edward D. Cope.

Charles Whitman Cross.

Henry P. Cushing.

Nelson H. Darton.

Frederick P. Dewey.

Edward V. d'Ixvilliers.

Edwin T. Dumble.

George II. Eldridge.

Samuel F. Emmons.

Herman L. Fairchild.

Moritz Fischer.

Albert E. Foote.

Homer T. Fuller.

Grove K. Gilbert.

Arnold Hague.

James Hall.

Robert Hay.

Eugene \V. Hil&ard.

Robert T. Hill.

Charles H. Hitchcock.

Joseph A. Holmes.

Horace C. Hoyey.

Edwin E. Howell.

Joseph P. Iddin<.<.

Joseph F. James.

Lawrence C. .Johnson.

James F. Kemp.

Charles R. Keyes.

Frank H. Knowlton.

Alfred C. Lane.

Andrew C. Lawson.

Joseph LeConte.
Frank Leverett.

JOSUA LlNDAHL.

W J McGee.

Othniel C. Marsh.

Frederick J. H. Merrill.

George P. Merrill.

Thomas F. Moses.

Frederick H. Newell.

Edward Orton.

Richard A. F. Penrose, Jr.

William H. Pettee.

J. W. Powell.

William North Rice.

( Iharles W. Rolfe.

James M. Safford.

Rollin D. Salisbury.

Nathaniel S. Shaler.

Eugene A. Smith.

J. W. Spencer.

John J. Stevenson.

Ralph S. Tarr.

Asa Scott Tiffany.

James E. Todd.

Edward 0. Ulrich.

Warren Upham.

Charles R. Van Hise.

( Jharles D. Walcott.

Lester F, Ward.

Charles A. White.

David White.

Israel c. White.

Robert P. Whitfield.

George H. Williams.

Henry S. Williams.

J. Francis Williams.

Bailey Willis.

Horace Vaughan Y\ 'inchell.

Newton H. Winchell.

Arthur Winslow!

John E. Wolff.

(152)

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 153-172, pls. 3-5

PRELIMINARY NOTES ON THE DISCOVERY OF A VERTE-
BRATE FAUNA IN SILURIAN (ORDOVICIAN) STRATA

CHARLES D. WALCOTT

ROCHESTEB

PUBLISHED BY THE SOCIETY

M \it.ii, 1892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP 153-172, PLS. 3-5 MARCH 15, 1892

PRELIMINARY, NOTES ON THE DISCOVERY OF A VERTE-
BRATE FAUNA IN SILURIAN (ORDOVICIAN) STRATA.

BY CHARLES I). WALCOTT.

( ( )XTEXTS.

Page

History of the Discovery 153

I Ascription of the Locality 155

The Harding Quarry Section 155

The Invertebrate Fauna 158

Harding' Sandstone L58

Fremont Limestone 159

Recapitulation 1(>2

The Vertebrate Fauna 163

l General Character , 163

Mode of Occurrence 1 (54

Position in the geologic Series. ]f>4

Notes on the ichthyic Remains 165

Descriptions of the ichthyic Fauna 165

I >iscussion 168

History of the Discovery.

The first discovery known to me of lower Paleozoic fossils in the vicinity
of ( Janyon ( 'ity. ( lolorado, was made in 1887 by Mr. S. F. Emmons, of the
United States Geological Survey. The collection included two species of
la nielli I tranch shells and one species of gasteropod. After examining the
specimens. 1 requested Mr. Emmons to have a larger collection made
from the same horizon, as the species indicated an unrecognized Paleozoic
fauna in Colorado. Mr. T. W. Stanton was employed by Mr. Emmons
to collect from the sandstones and limestones above the Ardiean. and a
collection was sent in by him accompanied by a sketch of several sections.
About the same time Mr. I. C. Russell, of the Geological Survey, while
stopping al Canyon City, collected from the lower sandstone a number of
specimens of lAngula and several portions of the calcified covering of what
is now considered to be the chordal sheath of :i fish. The preliminary

X \ - I'.i i i . <.i ,., . Bin \ m . Voi :, 1801. | | 5

154

('. ]). WALCOTT — DISCOVERY OF SILURIAN VERTEBRATES.

k~>

'".

":'

■? 3 P

2 M

^ ~

~ o *

- ft

- ■ -i
c3 0 g
2 2 X

-: - —

ra — - i

C<3

p —

o "

.2 fe

a -

I. -

CO o (JJ <S

q
I

t. —

- §

i
o

3D ^_-

- - = z

zr i.

r\ —
— O

*s * - i

d ft

examination of the collection
obtained by Mr. Stanton proved
the presence of the Trenton
fauna in the limestone series
above the sandstones. When
examining a small fragment of
sandstone upon which some
lamellibranch shells occurred I
discovered upon the lower side
what appeared to be fragments
of placoderm fish plates. Mr.
Stanton was then requested to
make a larger collection from
the sandstone and to carefully
review the stratigraphy of the
section. This he did, and from
his stratigraphic sections it was
evident that the fish remains
occurred beneath an inverte-
brate fauna having a Trenton
fades, and an examination of
the material disclosed the pres-
ence of a large number of plates
of placoderm fishes of the types
of those of the lower Devonian
fauna.

Owing to the great interest of
the discovery, and in order to
make myself fully acquainted
with the succession of the strata
and mode of occurrence of the
faunas before it was announced.
I went to Canyon City in De-
cember, 1890, and studied the
section in detail and collected
largely from the lower sand-
stone and the immediately
superjacent limestone. Mr.
Stanton's stratigraphic sections
were verified, and the debris
was cleared away at critical
points so as to photograph the

ROCKS ABOUT CANYON CITY. 155

contact of the sandstone with the subjacent pre-Paleozoic rocks and with
the superjacent shales and limestone; views were also obtained of the
entire section from this point to the overlying Carboniferous limestone.
After my return a brief notice of the presence of an icthyic fauna near
Canyon City, Colorado, in association with an Ordovician fauna was read
before the Biological Society of Washington on February 7th, 1891.

Description of the Locality.

( anvon City, Colorado, is situated near the southwestern shore of a bay
of early Silurian (Ordovician) and probably also of pre-Cambrian time.
The outcrop of pre-Cambrian rocks of the Rocky mountain front breaks
away south of Pikes peak and sweeps with a broad inward curve to the
westward, and thence southeastward past Canyon City before extending
eastward to the meridian of Pikes peak. Along the central part of the
western shore of this bay sediments were deposited, in Silurian (Ordovi-
cian) time that at present form massive beds of sandstone and limestone
extending several miles northward and southward on the flanks of the
pre-Cambrian or Algonkian rocks west and northwest of Canyon City.
The valley of the Arkansas river cuts the outcrop a mile wesl of the town
and erosion has removed it in places, but it is practically continuous for
ten miles north of the river, and isolated outcrops occur three miles
southward toward and into Webster park. The typical section was
measured in the immediate vicinity of Harding's quarry, which is about
one mile northwest of the state penitentiary at Canyon City.

The Hakdixo Quarry Section.

The section begins near a spring a little way west of the Harding sand-
stone quarry, and is carried on the strike of the beds so that it terminates

nearly a mile north of the quarry. This is done in order to secure con-
tacts from layer to Layer all the way from the base to the summit. The
basal bed of sandstone rests unconformably upon Algonkian bedded
gneiss and micaceous schists that dip to the eastward at high angles.
60°-75°. The succession is as follows:

Feet.

I . <i — ( !oarse, light gray sandstone 5

l) — Compact thinly bedded reddish anil gray sandstone passing into a
-ray ami more massively bedded somewhal friable sandstone thai
changes, a1 "_'•"> feel up, into a purplish-tinted somewhal coarse fria-
ble sandstone (strike, X. L0° E. (mag.) ; dip, 40 E.) 33

Fossils. A few scattered fish scales were noticed in the purple
beds ami Lingula attenuata, Salter (?), 20 feel from the base.
The beds are penetrated by an immense number of annelid
borings, ami the surfaces of the purplish-tinted layers are often

156 C. I). WALCOTT — DISCOVERY OF SILURIAN VERTEBRATES.

Page,
a network of the casts of the borings. On the southern side of
the Arkansas river, two miles south of the section, there were
found in a stratum 20 feet above the Algonkian rocks numerous
laniellibranchs, a few gasteropods, and numerous fragments of
the plates and scales of placo-ganoid fishes. ,

c — Reddish-brown sandy shales that arc partially calcareous in some

layers 7

Fossils. — Fish plates in great abundance and, in the calcareous

layers. Orihoceras multicameratum, Hall (?), BeyricMa (like />'.

fabulites, Conrad), and several species of lamellibranchs (sec

list, page 158).

d — Massively bedded gray and reddish sandstone, with thin irregular

beds of reddish-brown sandy shale in the lower portion 20

Fossils. — Fish plates and scales of fish are numerous in the
lower portion and also in a reddish-brown capping of the mas-
sive bed in which the Harding quarry is located. The supposed
chorda] sheaths occur scattered through this bed and also more
rarely in /», c and < .

» — Fine-grained argillaceo-arenaceous shale .'!

< rray and buff sandstone 7

— 10
/ — Coarse purplish-tinted sandstone in several layers, with gray layers

a hove 11

Fossils. — Plates and scales of fish.

Total sandsti me 86

Observations on thi Harding Sandstone Series. — The Lower bed is a shore-
line deposit following the advance of the sea upon the land; it is
formed of coarse -rains of quartz and small quartz pebbles imbedded
in a fine arenaceous matrix. The succeeding layers of sandstone have
more or less calcareous matter in the matrix. Their contained aceph-
alous shells, drift-worn plates and scales of fishes, and the vast num-
ber of casts of annelid borings, all prove the littoral origin of the
sediments. The fish plates and scales are scattered more or Less
throughout the beds, but they are very abundant in four principal
/ones, viz, c of the section : near the base, and again near the summit
of d; ami ai the summit of ,. in e they are commingled with re-
mains of Orthocei-as and with acephalous mollusks and gasteropods.
The closing deposit of the sandstone series is formed of a coarse drifted
sand, containing numerous fragments of larger fish plates than those
below. The change to the succeeding shaly beds is abrupt, and appar-
ently due to the deepening of the water and the cessation of arena-
ceous deposits.

'_'. Red and purple tine-grained argillaceo-arenaceous shale 2-4

Fossils. — Rolled and worn fragments of fish plates occur in
the lower portion.
:!. Graj silicious magnesian limestone, somewhat ferruginous in the
lower portion. Locally, this decomposes to a reddish, friable rock
and soil : the entire mass above 25 feet from the base weathers into
rough, irregular cliffs with numerous shallow caverns and holes of
various sizes and forms 170

FOSSILS OF THE FREMONT LIMESTONE. 157

Page.
Fossil*. — The lower layers are, in places, made up largely of
the casts of corals and inollusks, but well preserved specimens
are rare. Corals were observed in abundance in the lower LO
feet of the limestone on the northern side of the road leading
from Canyon City to Parkdale, a little east of where it enters on
the pre-Paleozoic rocks. In the lower three feet at the Harding
quarry and immediately toward the north there have been col-
lected the species mentioned in the list, pages 159, 1(50.

4. " — Tlii' upper portion of 3 passes into a hard, compact, light-colored lime-

stone 45

Fossils. — Zaphrentis and fragmentary casts of gasteropoda.

I/ — Dark reddish-brown sandstone 10

'• — Compact, hard light gray limestone breaking into angular fragments
and with a band of purple and gray calcareo-arenaceous shale at the

hase 45

Fossils. — A large and varied fauna occurs of a Trenton type
(see list, pages 161, 162).

5. Impure variegated banded limestone with interbedded sandstones and

argillaceous beds 15-30

Fossils. — Spirifera rockymontana, Athyris subtilita.

Observations on tin' Fremont Lino stone Series. — The line of demarkation
between the upper beds of the Silurian (Ordovician) and the super-
jacent limestones in which Carboniferous fossils occur is not stronglv
defined, although it represents a long period of non-deposition and a
great time break. The Carboniferous limestones are sometimes brec-
ciated and lithologically unlike those below. No traces of the Silurian
and Devonian groups have been obtained.

The bed of shale (number 2 of the section) is very persistent along the
six miles of outcrop examined. Fragmentary fish plates and scales occur
in the lower portion, but they were not observed in the upper part nor
in the superjacent limestones. The shale appears to include the closing-
deposit of the ichthyic fauna in this region.

The basal layer of limestone resting on number 2 is in many place-
almost entirely made up of easts of fossils that crumble into a red dust
when the rock is broken. At a few localities they are better preserved,
and 54 species in all were collected. Traces of fossils occur all the way
through the 170 foot of impure limestone, but it is not until the upper
portion of number I of the section is reached that well-preserved speci-
mens occur, [n number 4c, 57 species have been recognized, only 7 of
which occur in number 3.

Tlie el i a racier of the set limeiil s from the basal sandstone to the upper-
most Layer of limestone beneath the Carboniferous breccia indicates t hat
they were deposited in a hay or interior sea that was protected from the
<>p' 'I i ocean. A Iter the epoch of t lie a c< a 1 1 1 1 1 1 la t ioi i of t he beach sands and

158 C. D. WALCOTT — DISCOVERY OF SILURIAN VERTEBRATES.

-hales the water deepened, the iehthyic fauna disappeared, and the typical
invertebrate fauna of the Trenton epoch of New York nourished and was
imbedded in the calcareous sediments. The study thus far made of the
upper portion of the Silurian (Ordovician) section and the Carboniferous
strata has not shown the presence of Silurian or Devonian strata. If
deposited in this region they were eroded away by the Carboniferous sea.
The study of the breccias resting on the Carboniferous, or forming its
upper portion, may possibly throw some light upon this interval. Mr.
Stanton considers that the detailed sections give evidence of at least two,
and perhaps three, periods of upheaval and erosion from the Silurian
(Ordovician) to the Trias, inclusive.

The Invertebrate Fauna.

Harding Sandstone. — The invertebrate fauna of the sandstone series is
molluscan with the exception of one species of crustacean. As would be
expected in such a deposit, the acephalus mollusks number more than
onedialf of the species of the entire fauna. The largest number of speci-
mens were collected in h and rf of the section, figure 1. The fauna has
been partially identified and will be more thoroughly studied when the
collections now being made are available. The genera and species
recognized are as follows :

BRA< JHIOPODA.
Lingula, like /.. attenuata, Salter, and L. belli, Billings.

/. . 1 MELLIBRA NCHIA TA .

Modiobpsis, like M. trentonensis. Cypricardites,2 sp. undet.

" •". sp. undet. Orthonota, sp. undet.

< ypricardites, like C. ventricosa, Hall. Tettinomya, 3 sp. undet.
like C. rotundata, Hall.

GASTEROPODA.

Helicotoma, >\>. undet. Murchisonia, sp. undet.

Pleurotomaria, sp. undet.

CEPHALOPODA.

Orthoceras multicameratum, Hall. Oytoceras, sp. undet.

( RUSTACEA.
Leperditia, type of L.fabidites, Conrad.

FOSSILS OF THE HARDING SANDSTONE. L59

Summary.

., ., Species

( >i in r<i. Species. ■ , .-,- ,
' identified.

Brachiopoda I 1 1 (?)

Lamellibranchiata 4 1- '■'>

< rasteropoda 3 3 0

( tephalopoda - - 1

< Irustacea l 1 1

Total 11 l'.» 6

Recurrent above 9 1 1

Limited to 2 18 5

The presence of forms apparently identical with Lingula attenuata,
Modiolopsis trentonensis, Cypricardites ventricosa, C. rotundata, Orthoceras
multicameratum, and Leperditia fabulites leads to the conclusion that the
Trenton fauna is represented, and (from the known range of those species
in the New York section) that the fauna is lower Trenton or that of the
Black River and Birdseye limestones. This is further sustained by the
occurrence of the Trenton fauna higher up in the section.

Only one species (Orthoceras multicameratum) is known to range upward
into the limestone, although it is probable that some of the species of
Lamellibranchs may be found to be identical in the two formations.

Fremont Li tinstone — The fauna of the base of the limestone, number 3
of the section, extends through some earthy and semicrystalline layers
ranging from 4 to 10 feet above the upper bed of sandstone. It is large
and varied, and contains the following genera and species, as determined
in the preliminary study of the fauna:

PROTOZOA.

Stromatopora, sp. undet. Receptaculites, sp. undet.

Receptaculites oweni, Hall.

ACTINOZOA.

Streptelasma, sp. undet. Phyllopora, sp. undet.

Zaphrentis, sp. undet. * Columnaria alveolata, Goldfuss.

* Halysites catenulatus, Linn. Favosites, sp. undet.

Monticulipora, sp.? Heliolites, sp.?

ECHINOZOA.

Echinosphaerites, n. sp. Glyptocrinus, sp. undet.

BRACHIOPODA.

Strophomena alternata, Conrad. Orihis tricenaria, Conrad.

Streptorhynchus JUitextum, Hall. " sp. undet.

160 C. D. WALCOTT — DISCOVERY OF SILURIAN VERTEBRATES.

BRACHIOPODA— Continued.

Streptorhynchus sulcatum, Verneuil. *Rhynchonella capax^vax. ijicrebescens,

sp. undet. Hall.

Orthis biforata, Schlotheim. Rhynchonella dentata, Hall.

flabellum, Sv. ? Camarella, sp. undet.
* " subquadrata, Hall.

LAMELLIBRANCHIATA.

Ambonychia bellastriata, Hall. Modiolopsis, 2 sp. undet.

2 sp. undet. Cypricardites, 2 sp. undet.

Modiolopsis iiltiiHt. Hall. Tellinomya, sp. undet.

GASTEROPODA.

Metoptoma, sp. undet. Cyclonema bilex, Conrad.
Helicotoma (casts of the interior). " percarinata, Hall ?

Murchisonia tricarinata, Hall. sp. undet.

2 sp. undet. Bellerophon bilobatus, Sow.

CEPHALOPODA.

^Endoceras proteiforme, Hall. Gomphoceras powersi, James?
Ormoceras tenuifilam, Hall. " sp. undet.

crebriseptum, Hall? Cytoceras, 2 sp. undet.

Orthoceras vertebrale, Hall. IAtuites, sp. undet.

midticameratum, Hall.

TRILOBITA.

'■'-. [saphus, like .I. platycephalus (frag- Lllsenus crassicauda, Wahlen.
ment of pygidium). * " mitteri, Billings.

Summary.

. , o • Species

' '"■ '>'•"*• ;,/,„//,/,,/.

Protozoa 2 •*! 1

Actinozoa 8 8 2

Echinozoa 2 2 0

Brachiopoda 5 12 9

Lamellibranchiata 4 !• 2

Gasteropoda 5 it 4

Cephalopoda 6 9 ti

Trilobita 2 :; 2

Total 34 55 26

Recurrent above 19 9 !>

Cun lined to 15 4ii 17

FOSSILS OF THE FREMONT LIMESTONE. 101

( )f this fauna Halysites catenidatus, Columnaria alveolata, Strophomena
alternata, Streptdrhynchus filitextum, Orthis subquadrata, Rhynchonella capa
var. increbescens, Endoceras proteiforme, Asaphus platycephalus (?), and
Illsenus milleri extend up to the next strongly marked fossiliferous horizon,
215 feet above. Without exception, all these species have an extended
vertical range in the Silurian (Ordovician) strata either in North America
or Europe. The fact that 25 of the 27 identified species arc identical
with those of the Trenton fauna of Wisconsin and New York is sufficient
to locate the horizon in the Ordovician fauna. Halysites catenidatus is not
known from the Trenton zone elsewhere in America; hut in Wales it
ranges through the Bala and the subjacent Llandeilo. Orthis flabellumis
also a Bala species. There is nothing among the unidentified species to
indicate a higher horizon than the Trenton of the New York section.

Scattered and fragmentary fossils occur in the 225 feet of superjacent
limestone; hut it is in the beds 225 to 24N feet above the Harding sand-
stone that the fauna is best preserved. From this zone the following

species have heell collected :

ACTINOZOA.

Streptelasma cornicidum, Hall. Pleurodictyum, n. sp.

" 2 n. sp. Halysites c<if<'iiiilaiii*. Linn.

Columnaria alveolata, Goldfuss. Monticvlipora, 2 sp. ?
Favosites gothlandicus, Lamark.

ECHINOZOA.

Loose plates or segments of crinoi- Cyclocrinus, sp.'.'

dal columns.

BRACHIOPODA.

Leptsena sericea, Sowerby. Streptorhynchus planoconvexus, Hall.

sp. undet. " planumbonus, Hall.

Strophomena alternata, Conrad. " subtentum, Conrad (?).
alternata var. nasnta, Orthis subquadrata, Hall.

Conrad. " testudinaria, Dalman (?).

Strophomena deltoidea, Conrad. Rhynchonella capax, Conrad.

Streptorhynchus filitextum, Hall. capax var. increbescens,

nutans, .lames. I [all.

LAMELLIBRANCHIATA.

Pterinea, sp. undet. Tellinomya ventricosa, Hall.

Tellinomya dubia, Hall (?). Cypricardites, '■'> sp. undet.

levata, Hall (?). Modiolopsix faba, Conrad.

naxnta, Hall. " sp. ?

XXI Hi i i. Soi . \m . Vol . :. 1891.

L62 C. D. WALCOTT — DISCOVERY OF SILURIAN VERTEBRATES.

GASTEROPODA.

Metoptoma, sp. andet. Murchisonia, •"> sp. undet.

Helicotoma planulata, Salter. Subulites (J), sp. undet.

sp.? Bucania bidorsata, Hall.
Trochonema beachi, Whitfield (?). " ZmeZft, Whitfield.

Murchisonia milleri, Hall. Cyrtolites, sp. undet.
pagoda. Salter.

CEPHALOPODA.

Orthoceras annellum, Conrad. Endoceras proteiforme, Mall.

junceum, Hall. Gomphoceras, sp. ?

CRUSTACEA.

1. 1 perditia, sp. ?

TRILOBITA.

Ceraurus icarus, Billings. Asaphus platycephalus, Stokes.

sp. ? '• megistos, Locke.

Bathyurus (J), sp. undet. Tllsenus milleri, Billings.

/Vo,Mx (/). Sp. ?

Summary.

., . , Siiirns

< n in I'll. Sni rn s. ■ i . . ,
' identified.

A.ctinozoa i> '•' 4

( Jrinoidea 1 1 < >

Brachiopoda 6 12 11

Lamellibranchiata 4 LO 5

Gasteropoda 7 13 i>

( lephalopoda 3 4 •">

Crustacea 1 1 0

Trilobita 5 7 4

Totals 33 57 33

This fauna is distinctly of a Trenton facies, but as a whole it is upper
Trenton or Lorraine rather than lower Trenton.

Recapitulation. — On assembling the faunas of the three fossiliferous
zones, the distribution of genera and species is found to be as follows:

, , o • Sjtirii S

Genera, opecies. ■ , ,->■ ,
' identified.

Harding Sandstone 11 19 6

Fremont Limestone (lower portion) 34 55 27

upper portion) 33 7,7 33

78 131 66

Recurrent 28 10 10

Total fauna 50 121 56

CORRELATION OF THE INVERTEBRATE FAUNA. L63

An analysis of the fauna will not be attempted at present, as the col-
lections now being made will enlarge the data for comparisons, and the
final study of the fauna will result in the identification of a greater
number of species. I think sufficient data are given clearly to prove that
the invertebrate fauna of the Harding sandstone corresponds to that of
the lower Trenton of the New York section or the lower Bala of Wales.
The fauna of the two limestones is to be compared to that of the middle
and upper Trenton of America or the Bala of Europe. It is not to be
expected that an absolute correlation can be made of all the genera and
species common to the Colorado, Mississippi valley and New York sec-
tions. The vertical range of some genera and species will be found to
vary, but as a whole the succession is the same in the several sections.

The discovery of so huge and varied a fauna of Trenton fades is of
great interest, irrespective of its bearing on the stratigraphic position of
the ichthyic fauna, it clearly proves the continuation of the fauna of the
Trenton sea from Wisconsin, Iowa and Missouri to the western side of
the great interior sea.*

The range of Halysites catenulatus has hitherto been considered to be
limited to the Niagara terrane of the American Silurian, and it has often
been the sole means of identifying that horizon. With the extended
ranse it is now known to have in the Ordovician fauna of Colorado we
can speak less confidently of the stratigraphic horizon identified by its
presence. In Wales and England it ranges from the Llandeilo through
the Bala or Caradoc.

Tin'. Vertebrate Fauna.

General Character. — The evidence of the existence of vertebrates at this
early epoch is limited to the plates and scales of ganoid fishes and what
appears to lie the ossified chorda] sheath of a fish allied to the recent
Chimzera. The latter correlation is based entirely upon the resemblance
between the fossil form and thecalcified chorda! sheath of Chimxra mon-
strosa. This resemblance is too striking to be passed over, although there
are certain differences thai render it of less value in classification than at
first appears. The Holoptychius-like scales and the Asterolepis-like plates
are their own interpreters and prove their connection with the lower
Devonian types with which they are compared. They are clearly the
diminutive. ancestral types of the greal fishes thai ;it a later date swarmed
in the Devonian sea and left their remains in the classic u Old Red
sandstone."

* Quito recently I received from Professor F. II. Carpenter Haclureo nd Endo

latum that were collected from a hand 6f limestone beneath tli it ol the Blael Hills

of South Dakota, thus establishing unothi i owtposl in the Trontou

104 C. D. WALCOTT — DISCOVERY OF SILl'KIAN VERTEBRATES.

Mode of Occurrence. — The stratigraphic section shows the vertical range
of the fish remains to be from about 20 feet above the base of the .sand-
stone to its summit and one or two feet into the superjacent argillaceous
shale; in all, 75 to 80 feet in the Harding quarry section. The horizontal
distribution extends along some eight miles of outcrop west of Canyon
City, and another locality was discovered 150 miles to the northwestward,
by Mr. George II. Eldridge, on Cement peak, southeast of Crested butte,
Gunnison county, Colorado. Tins locality is now under investigation.

In the Harding sandstone the fish remains are most abundant in a
reddish, sandy shale that occurs in irregular bands at several horizons.
They are also scattered irregularly through the more massive beds. Tins
is the ease with the chordal sheaths more than with the plates and scales.
The latter visually occur in great numbers with only a few traces of the
former, while in the massive sandstone the plates and scales are infre-
quent and the sheaths more or less abundant. The invasion of the sand
in large quantity appears to have overwhelmed the ChimseraAike fish
and acephalous mollusks, while the armor-plated fishes, gasteropods and
cephalopods, escaped to subsequently perish and have their remains
rolled about by the currents spreading the thinner and finer sandy layers.
The acephalous mollusks and the sheaths occur in the latter, but less
frequently. In the upper bed of coarse sandstone numerous plates and
fragments of plates occur, but all are more or less injured by the tritura-
tion of the sand as they were rolled along with it. The same is true of
the greater portion of the fish remains in all the shaly bands. As yet
no bed has been discovered where the conditions were favorable to the
preservation of the united plates or scales forming the armor of the fish.*
The chordal sheaths show less evidence of abrasion, but no other portions
of the same fish have been found with them.

The invertebrate fauna associated with the fish remains is largely
molluscan and of sand-loving types. The exceptions to this are found
in the shaly beds where the rolled fragments of gasteropods and cepha-
lopods indicate transportation from a more congenial habitat. The
numerous specimens of Lingula and of lamellib ranch shells and the vast
number of annelid borings in some portions of the sandstones indicate
the conditions of the deposition of the massive layers, while the shaly
bands denote the period of minimum deposition and maximum accumu-
lation of the fragmentary fish remains and the rolled fragments of in-
vertebrates.

Position in f/n geologic Series. — This has already been determined by
the study of the invertebrate fauna. The fish remains occur at the
horizon of the lower Trenton in America, or the relatively similar hori-
zon, the lower Bala of Wales.

* A single specimen of Axtraspi* d* tid< r<it*i has liccii i'oii ml since this paragraph was written (p. LC7).

COliRELATION OF THE VERTEBRATE FAUNA. 165

Notes on tJu ichthyic Remains. — Fishes have been found in the Ludlow

rocks of the Silurian of England and in the Bloomfield sandstone of
Pennsylvania in America, a horizon of the upper portion of the Onon-
daga salt group. Professor E. W. Claypole lias also described certain
minute spines which he considered might belong to an elasmobranch fish
that he found in the Clinton terrane* The evidence, however, is not
conclusive, as they may belong to some crustacean.

It is to he noted that the middle Silurian forms thus far found be-
long to the two families Pteraspididse and Cephalaspididse, and that no
representative of the great placoderms of the Devonian has been found
in the true Silurian. In strong contrast to this the ichthyic fauna of the
Harding sandstone appears to contain a characteristic representative of
the Placodermata and Crossopterygea "I' the Devonian, and what appears
to he a type of the Chimseroidae. Serious objection will undoubtedly
he made to the classification, as it is based entirely upon the characters
of the dermal plates and scales. These, however, are so pronounce:!
that the classification is tentatively adopted. The vertical range of tin'
ichthyic fauna is extended downward from the middle ( Upper) Silurian to
the base of the Lower Silurian (Ordovician), and the conclusion is reached
that the differentiation of vertebrates and invertebrates must have begun
in ( 'amhrian time.

Pending the investigation of the beds containing the fish remains and
the collection of more material, it is not desirable to illustrate the inverte-
brate fauna or to do more than outline the characters of the fragmentary
fish remains. For convenience of reference to the latter, names are applied
to three of the most marked forms and illustrations are given of typical
fragments of these forms. The classification is tentative.

Since some doubt was expressed, during the discussion, as to the true
zoologic character of the dermal plate-, microscopic sections were made
of the tuberculated Asterolepis-Yike forms. These showed microscopic
characters much like those found in the Devonian Asterolepis, and Dr.
Otto -lack el kindly offered to make a few sketches and write ;i brief note
upon them.f

Descriptions ok the echthyic Fauna.
CHIMjEROIDEA.

DICTYOKHABDUS PRISCUS. N. (JEN., V SP.

This genus and species is based on a calcified chorda] sheath that has
some of the structural characters of the chorda! -heath of Chi nitrra mon-

*Quurt. Jour. '■•'•! 801 I Ion, \..l 11, 188ii p 1-

1- 11.. i.- i~ nppptuli •! 1- 1 1 • ' 11 "l l'i .l:i.-K.'l- .li-. 11--1..1, « - 1 ■ LU8 170).

16(3 C. D. WALCOTT — DISCOVERY OF SILURIAN VERTEBRATES.

strosa, except that it is open below and gives rise on the sides to what
appears to have been the support of the ribs. Further description will
be given in a final paper.

The principal material upon which the genus and species are founded
is illustrated on plate 3. Figure 1 is a side view of a portion of a rather
large sheath. It shows the close transverse rings and the projecting
lateral rib sockets or supports. Figure 2 is a view from above of a por-
tion of the -heath shown in figure 1 to display the form and arrangement
of the lateral rib sockets or supports. Figure 3 is an enlargement of the
surface of a chorda] sheath to showthe characteristic network formed by
the crossing of the two series of elevated, raised, curved striae. It is con-
sidered that these represent the fibres of the sheath, while the vertical
rings shown in figures 1 and 5 are the calcified rings. The fusion of the
rings and the oblique fibers give rise to the continuous calcified sheath,
as in Chvniasra monstrosa. Figure 4" is a transverse outline of the chordal
sheath to show- that is was not closed on the ventral surface, ami figure
46 is a transverse outline cutting across the lateral extensions or rib sup-
ports. Figure 5 represents a portion of a small chordal sheath, showing
its flexible nature and indicating that the larger fish must have attained
considerable size.

GAN01DEA.

Si B-ORDER PlACODERMATA.

Family Asterolepidida I f).

ASTRASPIS DESIDERATA, X. si'.

This type is represented by fragments of plates allied to those of
Asterolepis ornatus of the Devonian.

The material upon which the species is founded is illustrated on plates
3 and 4. On plate 1 figure 6 shows the inner surface of a plate with a
portion broken away so as to exhibit the base and transverse sections of
the tubercles of the outer surface, and figure 7 represents the interior sur-
face of a plate for comparison with figure ('>. Figure 8 represents a frag-
ment of a supposed ventral plate of the body, figure 9 a plate referred to
the cephalic region, and figure If' a small elevated tuberculated plate.
Figure 11 shows the supposed inner surface of a plate similar to that
represented in figure 10. and figure 12 the inner surface of a plate similar
to that seen in figure 11. Figure 13 is a transverse section of a narrow,
elongate plate, showing a cellular structure and the projecting tubercles.
The latter expand at the summit into a round knob, the upper surface of
which is cut hv radiating stria', so as to give it a star-like Astrse-form

DESCRIPTION OF NEW SPECIES. K'x

appearance. This is move clearly shown in figure 14. which is a side
view of the knob-like Astrae-form tubercle of the outer surface when un-
abraded. On plate 1 figure 1 represents a dermal plate with two raised
tubercles and numerous small Astrse-form tubercles, and figure 2 is the
outer surface of a supposed lateral plate. Figures 3 and 4, plate 4, repre-
sent the outer surfaces of partially abraded plates*

SUB-ORDEK < JROSSOITERYGEA.

Family Holoptychidida. .

ERIPTYCHIUS AMKKK AXIS, X. -1'.

This species is hased entirely upon the separated scales. It is not im-
probable that several species are represented in the material, the better
preserved portion of which is illustrated in plate 4. figures 5 toll. Figures
") and 6 are broad scales, each showing the bearing surface or facet of the
next anterior scale and the ornamented exterior surface. The latter has
numerous elevated longitudinal lines upon it, Figure 7 is a fragment ol
a scale with irregular stellate surface ornamentation, and figure 8 another
fragment of a scale of the same type. Figure 9 is a phase of surface
ornamentation somewhat like that of figure 8, and figure 10 is an inter-
mediate phase of ornamentation between that of figure 7 and those of
figures 5 and 6. Figure 11 represents the interior of a narrow scale that
shows the poriferous inner surface and. where broken away, the base of
the elevated longitudinal lines of the outer surface.

Plate •"> illustrates the microscopic structure of the remains of both the
species discriminated.

♦ During the fall of 1891, a portion of the head earapae< "I A straspis desiderata was found in a

very fine grained calcareous sandstone. It measures 73mm in length bj " im in widthatthe

posterior margin and 40mm toward the front. It is formed by the union of a great number of small
plates, such as are illustrated "ii plate :;. figures 10-14. A median ridge formed "t elevated, tuber-
culated plates extends from the posterior margin 13mm toward the front, very much ;i- in tin- he id
shield of Thyestes verrucosus, Eichwald, from the Silurian rocks of the island of Oesel, Russia A

Miml ii' ridge occurs on each si. I.- that extends forward 28i from the posterior margin ; they are

13 i from tlir mediap ridge at tin- base and 9i from ii at their anterior termination A marginal

ridge occurs on each side of tin' specimen that i- continuous with tin- margin so far as (In- latter
is preserved. Directly in front of the median ridge a group of 12 plates having elevated cen
are clustered around ■■> central plate that rises at the center above tin- others. On each side of this
cluster "i plates a larger plate (4 x 6mm) occurs that has six elevated tuberculated points on it.
interior to this there is a plate with two points and another with three. Over other portions
the carapace tin- plates have usually only a single elevation near the center. The small Astra-
form tubercles occur on all the plates. "I he form "t tin- portion of the carapace preserved ami it~
appearance suggests tin- cephalaspian fishes "i the Silurian of Russia, while tin- separate plates and

i : , ., form tubercles foreshadow the Asterolepidse of the lower Devonian.— March, i -

DISC 'I rSSION.

Professor Dr. Zittel: I consider the fossils exhibited by Mr. Walcott
to be dermal plates and scales of fishes. They differ considerably from
everything hitherto known from -Silurian strata, and show a decided
resemblance to Asterolepis and Holoptychius of the Devonian rocks.
Microscopic slides are needed to show with certainty the osteoblasts and
the peculiar structure of the dermal ossifications of fishes.

Dr. .Frederick Schmidt: 1 agree with Professor Zittel that the fossils
are undoubtedly fish remains.

Professor E. W. Claypole: before we can admit the existence of fishes
during so early a period as the earlier Silurian, it will be necessary to
use every means to prove the ichthyic character of the remains, especially
the study of microscopic sections.

Professor E. D. Cope: It is very doubtful whether the remains of
crossoptergyian fishes occur at so low a horizon. I consider it essential
that the skeleton should he found before deciding that fishes were pres-
ent, as the dermal covering of the lower vertebrate is not a reliable char-
acter in classification.

Mr. Walcott: Microscopic sections are being made and will he fully
described in a final paper.- Moreover, Mr. S. Ward Loper is collecting
material in Colorado at the present time that may add materially to our
knowledge of the fauna.

Dr. Otto Jaekel : The remains in their exterior characters do not
recall the fish remains known from flu1 Upper Silurian, but rather those
of the Old bed sandstone. The resemblance to the latter becomes still
more striking for the reason that the two appear in the same kind of
rock and in like condition of preservation ; but on closer comparison of
the two it appears that the agreement is by no means so great as would
seem at first sight. The forms resembling each other cannot he identified,
and the fauna here spoken of exhibits types of microscopic structure
that are as foreign to the Devonian as to the upper Silurian. Still, this
much seems certain : that the pteraspidse and acanthodians, dominating
in the uppermost Silurian, are absent from this fauna ; whereas, on the
other hand, they ally themselves with the Devonian remains of Crosso-
pterygea and placoderms and of true ganoids. Not a single fragment
shows any resemblance with the placoid parts of the elasmobranchii.

* In response to an invitation from Mr. Walcott to discuss briefly the
micro-structure of the fish remains, 1 may observe, as regards the histo-

■ \ni irnmunieated after examining the slide!5 made from the fossils.

(168)

JAEKEL ON MICRO-STRUCTURE. 169

Logic state of preservation of the remains, it unfortunately leaves much
to be desired. In a general way. the fossils show merely the coarser
histologic structure, while the finer details are for the most part invisible.
The material is in this respect somewhat in the same condition as the
Devonian fish remains from the Old Red sandstone of Scotland, in which
likewise the finer histologic details are usually not present, while in the
remains from the Russian Devonian they are finely preserved. The state
of preservation depends on the retention of the fine dentine and primi-
tive tubules ; and this again depends on their being tilled with air or
with a dark infiltrate. At times it is seen that in one part of the slides
the fine canals are completely preserved, while in the other parts of the
same preparation either (a) only single parts of the tubules are preserved
or (h) the tubules are altogether invisible. In such case the outlines of
the tubules are sometimes seen in oblique illumination. This is the case
with our fish remains. The fine details are mostly invisible, hut are
preserved in some parts and may then he easily recognized with an
oblique converging light. Add to this that all hard parts are more or
Less worn and probably changed in various ways by acids. This being
premised, the micro-structure exhibits the following conditions:

Figure 1 of plate 5 shows a vertical section through a scale or a cara-
pace fragment. In the upper part of the preparation there are seen
tubercles of dentine ( f)), containing a pulp'from which numerous den-
tine tubules run out. These are especially well preserved in part in the
middle dentine tubercle, while the outlines of the pulp appear greatly
corroded. These conditions are seen more distinctly in figure 2, in which
two dentine tubercles lying side by side are enlarged aboul 7'* diameters.
Here not only are the dentine tubules seen well preserved, hut the out-
line of the pulp, too, is unchanged. It is furthermore important to note
in them the concentric lamination, which appeal's in primary connection
with the dentine tubules. The concentric lamellae do not run in uniform
curves, hut arch independently between the dentine tubules, the curva-
ture being directly inward. Toward the outside the Lamellae run more
uniformly parallel to the surface. This concentric building up out of
lamellae appears with like distinctness in the dentine tubercle represented
in figure 3, which in its outer form reminds one of a tooth. It also
greatly recalls the teeth which are described by Rohon from the blue clay
of St. Petersburg. There can hardly he any doubt that this concentric
structure of the hard parts represent- a Low stage of development. At
any rate. I believe that the most essential difference between the calcified
hard part- of the lower animals and those of the vertebrates consists in
this: that in the former growth took place only by apposition, and that

XXII- !'•< m Gkoi 3oi \ .i . \ -i 3, 1891.

L70 C. D. WALCOTT — DISCOVERY OF SILURIAN VERTEBRATES.

they show merely a stratification of lamella? lying one above the other,
while in vertebrates growth takes place from within by special cells.
odontoblasts or osteoblasts. The fossil proofs for the former are the den-
tine tubules : for the later, the outlines surrounding the osteoblasts. The
former we saw in the dentine tubercles, figures 1-3 : the latter are dis-
tinctly recognized in figure 4. which is enlarged to about 350 diameters.
It plainly shows small, irregularly bounded hollow spaces with ramify-
ing and anastomosing shoots. These I can only regard as true osteo-
blasts, peculiar to the hard dermal parts of the ganoids, inclusive of
placoderms. Their existence might at once be conjectured from the
outer appearance of the remains. Of course only detailed investigation
can show whether they exist in all the remains here described. In the
cross-section shown in figure 1 they appear to be preserved in the lower
parts, yet their state of preservation there is far less perfect, so that their
existence can merely be designated as probable. Briefly speaking, the
observations show the following facts:

1. The existence of undoubted dentine tubules proves beyond doubt
that the remains, so far as they have been microscopically investigated.
belong to vertebrates.

2. The occurrence of true osteoblasts distinguishes these hard parts
beyond doubt from those of the elasmobranchii and relegates them to
the division of the ganoids. Enamel could not be found in the speci-
mens studied. On account of this and by the strikingly distinct concen-
tric lamination in the dentine tubercles, the hard parts investigated indi-
cate a low stage of development.

Professor James Hall:* In reference to the invertebrate fossils shown
me as coming in above the beds containing fish remains, I need only say
that they have a general Lower Silurian facies and represent in their
genera and species the fauna of the Trenton period, including Birdseye,
Black rivei-. and Trenton limestones. Some of them which were pointed
out as coming from the higher beds as exposed in the section seem tome
to be representatives of the Hudson River horizon ; for example, Orthls
(Plasseomys) subquadrata. The abundance and large size of the speci-
mens of Rhynchonella increbescens or R. capax seem scarcely compatible
with the strict limitation of the Trenton horizon. Comparing the lists of
the species which have been made, I can have no hesitation in coincid-
ing with the determinations, thus leaving no doubt whatever of the nature
and age of the deposits.

* A note communicated to the author.

II A I.I. OX FISH REMAINS. 171

With regard to the fish remains I hesitate to express any opinion
beyond this, that they have a remarkable similarity to Devonian forms.
The nature and mode of aggregation of the material in which they arc
imbedded has a most decided Devonian aspect, and had they been pre-
sented to me without other evidence, I should not have hesitated in ex-
pressing my opinion as to their Devonian age.

Description of Plates.

Piatt 3.

Figures 1- 5. — Various views of the supposed chorda! sheath referred to Dictyo-

rhabdus priscus, n. gen., n. sp.
Figures 6-14. — Dermal plates of Astraspis desiderata, n. sp.

Piatt 4-

Figures 1- 4. — Outer surface of partially ahraded plates referred to Astraspis desid-

• rata, n. sp.
Figures 5-11. — Various views of dermal scales referred to Eriptychius americanus,

n. sp. It may be that several species are represented.

Piatt 5.

Greatly enlarged drawings to illustratt Dr. Otto JaeJceVs remarks on tin microscopic char-

ii, -i, r& of 'In fossils. |

Figure 1. — < Toss-section through a plate with haversian canals [V), osteoblasts {0),

and dentine tubercles /' .
Figurt 2. — Two dentine tubercles enlarged to 70 diameters.
FigureS. — Oblique section of dentin* tubercle.
Figurt 4.— Enlargement to 350 diameters to show osteoplasts [O). The margin is

shown at a, a, and the rock at /.'. R.

(172)

BULL.GEOL . SOC.AM.

VOL. 3. 1891. FL.3.

V ',,ft'~': i .

si ■

kf§f|

•'liV^v''^

. _».Ji>.'WBU

• ■ . ' ■■

ti*. •. -' r .'

. v ■ • '- ;.-
'V

J-^ ■■' '■ i /if'

■

fc,»

l /

!((W

r^-K- — ■ — ~-_^

. *■ - \ ' 'J"

'-' ■-.'■ '.•:\ '•!

• ..■' 'V- ■

"4 :>5Y ;■,- - ■ '..■ ft ■■ IS v

SILURIAN ORDOVICUN FISH REMAINS FROM COLORADO.

BULL.GEOL. SOC.AM.

VOL.3.18S1.PU4;

M YV

J*C* ■»

6
I

($&$¥ j

ilfe*:;$;i

i ::&%■& TLMk H:W§ I- M

fjpli

USUI w^Bis

^d£^»

CaBSsl'S i i-Y • :"&;•&

;' » ■ : ' % " wk

mmm W

2 X >H Mil / "Fwm

1 1

ILUHIAN ORDIVICIAN fPH REMAINS FROM COLORADO.

BULL.GEOL.SOC AM.

VOL 3.1S91FL 5.

MICROSCOPIC SECTIONS OF SILURIAN 'ORDIVICIAN FISH REMAINS FROM COLORADO.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 173-182; pp. 183-186

CERTAIN EXTRA-MORAINIC DRIFT PHENOMENA OF NEW

JERSEY

ON THE NORTHWARD AND EASTWARD EXTENSION OF THE
PRE-PLEISTOCENE GRAVELS OF THE MISSISSIPPI BASIN

R. D. SALISBURY

ROCHESTER
PUBLISHED BY THE SOCIETY

M \k. ii, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP. 173-182 MARCH 31, 1892

CERTAIN EXTRA-MORAINIC DRIFT PHENOMENA OF NEW

JERSEY.

BY R. I). SALISBURY.

(Read before the Society August 25, 1891.)

< iONTENTS.

Page

Previous Opinions concerning the Drift Margin 173

Results of recent Studies • ■ 175

Critical Localities and Exposures 175

I )irect Evidence of Ice Work 179

Distribution of the Phenomena 1 79

Significance of the Observations 180

( reneral Bearing 180

Number of Ice Invasions 180

< orrelations of Deposits 182

Previous Opinions concerning the Drift Margin.

The terminal moraine running across New Jersey from Perth Amboy
to Belvidere, and continuing thence across Pennsylvania, was first traced
out under the auspices of the surveys of these stales. The work in New
Jersey preceded that in Pennsylvania, and was anion-' the earliest mo-
rainic studies. In both states the terminal moraine referred to was pub-
lished as representing the limit of glacial drift, and this conclusion.
announced by the surveys of the respective states, was accepted by geolot
prists as correct.

[nterpreting eastern phenomena by western, glacialists not intimately
familiar with the eastern field regarded the southern portion of the New
Jersey and Pennsylvania drift as belonging to the first glacial epoch.
The I'm et thai the glacial drift of the interior is not Limited on the south
by a terminal moraine was well known, and the southern limitation of
the eastern drift by a terminal moraine seemed to put the two regions in
Bharp contrast. Bui it was believed thai ifthe known moraine of New
Jersey and Pennsylvania represented the southern limit of the drift, other

Will Bon 1 3oi \m . Voi„ 3 1891 ' ' ""' '

174 R. D. SALISBURY EXTRA-MORAIXIC DRIFT.

moraines would be found toward the north equivalent to those of the
interior, and referred to a later ice epoch. Subsequently, whenglaeialists
familiar with the phenomena of older and younger drift sheets as devel-
oped in the interior came to study the drift of the states in question, the
terminal moraines of New Jersey and Pennsylvania and the drift north
of it were found to correspond in all essential points with the later glacial
drift of the interior instead of with the earlier.

Still proceeding on the belief that the moraine represented the southern
limit of the drift, it was inferred that the ice-advance of the later glacial
times was equal to or exceeded that of the earlier, and that therefore the
deposit of the latter was overridden and obliterated or obscured by the
former. This interpretation, however, has never seemed entirely har-
monious with the accepted interpretation of the drift phenomena of the
interior. President Chamberlin has more than once expressed the
opinion, though he has nowhere published it, that there might be an
older drift sheet south of the moraine in New Jersey and Pennsylvania
which had escaped observation. Two years since, with this suggestion
in mind, though primarily for another purpose, President Chamberlin
and the writer made a cursory examination of certain extra-morainic
areas in New Jersey and Pennsylvania. The result of this examination
was to strengthen the suspicion that glacial drift did not find its southern-
most limit in New Jersey and Pennsylvania along the line of the moraine.

The phenomena which were then observed have never been published.
The most significant fact developed was the existence of glacially striated
stony material many miles south of the moraine at one point at least in
New Jersey and at three points in Pennsylvania. The striated stones
were occasionally seen to be embedded in a matrix of clayey nature, re-
sembling till. This bowldery clay was of such a character and in such
positions as to make the suggestion of its derivation from the moraine
toward the north unsatisfactory if not altogether untenable. Some of
the phenomena seen were capable of explanation without supposing
glacier ice to have been present in the region where they occur: others
seemed to us to find their most rational explanation in the supposition
that glaciation had extended beyond the limit hitherto assigned it.

In June of the present year the writer visited New Jersey, and then
learned for the first time that Professor Smock had long entertained the
idea that there might be a formation of glacial drift south of the moraine
which he had traced across the state. Professor Smock was in possession
of a number of facts concerning the character of the surface formation
south of the moraine which afforded sufficient basis for the idea which
he entertained. When the writer undertook the detailed study of the
Pleistocene formations of New Jersey a little later in the season, 1'rol'essor

OBSERVATIONS OF CHAMBERLIN AND SMOCK. 175

Smock very generously put these facts into his jwssession. Their nature
was altogether in keeping with the facts which President Chamberlin and
the writer had independently discovered two years since, and Professor
Smock's inferences corresponded with our own.

Results of recent Studies.

Critical Localities and Exposures. — During the months of July and
August, L891, the localities which had raised the question of an extra-
Qiorainic glacial drift in Professor Smock's mind were visited by the
writer and examined in detail, and many other localities were found
where the same class of phenomena are to be seen. Some of these local-
ities, because of their geographic positions and relations, seem to be
crucial so far as the question of extra-morainic drift is concerned; and
although the work on the Pleistocene formations of New Jersey is hut
begUn, a few of the facts already developed arc thought to be of suffi-
cient importance to warrant statement before this Society.

At Oxford Furnace, at an elevation of between 500 feet and 600 feet,
there is an accumulation of surface material which is certainly not of
local origin, it is partly stratified and partly unstratilied. It contains
large bowlders of various kinds of rock, many of which show unmistak-
able signs «»f ice wear. They are so associated with clay that the un-
stratified portions of the material have the aspect of till. The relation of
the stratified to the unstratified material is such as may often be observed
in glacial drift.

This locality is not more than two miles south of the terminal moraine,
and its altitude is slightly less than that of the moraine. Since this is
the fact, and since the material is in part stratified, it might be inferred
thai the surface materials at ( )xford Furnace are not hing more than deriva-
tives from the moraine: but a critical examination of the material itself
is fatal to this hypothesis. If this material were derived from the moraine
by the action of water (an hypothesis which has found currency for simi-
lar formations similarly disposed elsewhere) its origin should he revealed
in it^ structure and composition : hut both its structure and composition
show that it is not overwash material. Much of it is unstratified, and
the relation of the stratified to the unstratilied parts is most complex and
not within the power of water, acting alone, to produce. Overwash
gravel plains "flanking the moraine are well developed in the vicinity.
and their constitution and structure are well known. They consist uni-
formly of water-worn gravel mingled with sand. Earthy material is
wanting. The unstratified material ;it < Ixford Furnace, on the other hand,
i- a tough bowldery clav with its stony material abundantly striated, and

L76 J!. D. SALISBURY — EXTRA-MORAINIC DRIFT.

the striae are of such a character as to make their glacial origin evident.
Even among the pebbles of the stratified portions of the Oxford Furnace
deposits, striated pebbles may occasionally be found, indicating that the

materials have suffered but a limited transport by water. Furthermore.
the relations of the stratified and unstratified materials are such as to
show contemporaneity of origin.

In another sense the morainic material and the material of morainic
derivation just north of Oxford Furnace are essentially unlike the Oxford
Furnace deposits. The one bears every evidence of youth, and the other
as strikingly bears evidence of age. In the one ease the days are unox-
idized and unleaehed. and the stony material retains the hard fresh sur-
faces which characterize freshly glaciated bowlders. Even the sands,
readily percolated by water, are calcareous to within three or four feet of
the surface. In the other case, the clays are oxidized to great depths,
the calcareous material which they presumably contained has been
leached out. and a large proportion of the decomposable rock materials
which the clay contains have so far yielded to the effects of weathering
and solution as to have lost their integrity altogether. So striking are
these differences in the two classes of deposits, good exposures of which
may be seen within two miles of each other, that it cannot escape notice
even in a cursory examination. If 1 represent the age of the material
of the moraine, the age of the other can hardly he represented by one
figure.

The higher lands southwest and west of Oxford Furnace are likewise
found to be interruptedly covered by a similar drift mantle. It is gener-
ally absent from the steep slopes, is frequently present on the gentler ones,
and is nearly uniformly present on the level summits. Rising from 550
feet near Oxford Furnace to 600, 7<»» and 800 feet, the same till-like ma-
terial occurs. Near Little York, about 860 feet above tide, the same
bowldery clay is exposed to a depth often feet or more. The stony ma-
terial is predominantly small, and the larger portion of the stone is of
quartzite or hard sandstone. The quartzites and hard sand-tone- do
not commonly show glacial markings, though their surfaces are gen-
erally unweathered and sometimes show planation. The fragments of
crystalline rocks (crystalline schist series) are almost uniformly so far
disintegrated that they would not show surface markings even if once
.present.

Among the stony ingredients at this place there .ire many hits of soft
shale. With these the case is very different. These hits of shale, soft as
they are, have withstood the disintegrating action of air and water, and
very many of them still preserve the surfaces they possessed at the time
of their deposition. Among the fragments of shale, large and small, it

ANTIQUITY OF THE EXTRA-MORAINIC DRIFT. 177

is well nigh impossible to find a piece which still preserves its original
surfaces that does not show glacial striae. Even tiny fragments but a
fraction of an inch in diameter arc found to be very generally marked.

When the softness of these shale fragments is considered and their
association with numerous pebbles and cobbles and bowlders of hard
sandstone, quartzite, etc, is borne in mind, it seems impossible to attrib-
ute their deposition to water. They are much too soft to endure even a
limited amount of transportation by water without having their scorings
obliterated. Much less could they stand water transportation along with
hard materials, such as those with which they are associated, without
having every trace of glacial striation effaced. If any added evidence is
needed to prove their non-aqueous origin, that evidence is found in the
shape of the fragments and in their association with materials of all
grades of coarseness and fineness without trace of stratification.

The chemical and physical condition of the material near Little York
is like that of the corresponding deposits near Oxford Furnace. The
decomposable rocks have yielded to the influence of weathering and
have lost their integrity. The clay is oxidized to the depth of the ex-
posure and is wholly wanting in calcareous material. If this was ever
present, it has been completely abstracted ; in short, every feature of the
material indicates age. On this ground alone it is impossible to think
of it as having any genetic connection with the moraine. Furthermore,
it is more than 100 feet higher than the moraine three miles or so north-
ward. It is therefore physically impossible for it to have been derived
therefrom by aqueous agencies. In the same vicinity bowlders like those
of the till-like clay which lias been identified up to elevations of 860 feet
exist up to heights of 1,000 feet and more. In other words, the bowlders
occur on the tops of the highest hills and ridges. Above Nf>0 feet thev
were not seen in association with clay, but this is believed to be because
of the absence of exposures. So far as surface indications afford criteria
for judgment, there is every reason to believe that the bowldery clay is
presenl on the highest lands in the vicinity, wherever they have not been

subjected loa great degree of erosion.

Near .Mount Bethel, a point five or six miles east of Oxford Furnace,
the same type of bowldery clay, containing striated material, was seen at
a height of about 960 feet. Like ( )xford Furnace, this is but two or three

miles fr the moraine, but is several hundred feet above that pari of

the moraine which is nearest to it. As at Little York, the material is
here wholly mist ra t i lied SO far as exposed, and it OCCUrS a1 the great e-t

elevations where exposures were found, bowlders may he seen at the
surface on the tops of the highesl hills visited in the vicinity, fully 100
feel above tin1 highest exposure of the bowldery clay -ecu. It i> alto-

178 R. I). SALISBURY EXTRA-MORAINIC DRIFT.

gether probable that the bowlders seen between 1,000 and 1,100 feet
above tide are an index of bowlder-bearing clay existing here though
not exposed.

Farther southward the same type of material occurs in the Pohatcong
and Musconetcong valleys. Lf well data may be relied upon, there is as
much as 70 feet of it in the valley near Washington, at an elevation of
about 400 feet. From the localities cited it will be seen that the vertical
range of the material is great within narrow geographic limits — fully
600 feet within six miles.

Still farther southward, near High Bridge, at an elevation about equal
to that at Washington, or about 200 feet above the valley of the Raritan,
dose at hand, there is an exposure of about 30 feet of bowlder clay and
gravel. As at Oxford Furnace, the material is here partially stratified,
Imt a considerable proportion does not show any sign of orderly arrange-
ment, and the bowlders are disposed in the clayey matrix after the
fashion of true till. Bowlders five or six feet in diameter occur. One
bowlder, whose greatest dimension is fully 7 feet, is glacially striated over
nearly the whole of one face. As at Little York, so also here, one of the
ingredients of the bowlder clay is shale in large and small fragments.
Here also, as at Little York, it is difficult to find a piece of shale which
retains the form it possessed when deposited which does not show ice
scorings. In more than one instance bowlderets of shale were seen in
situ showing glacial markings with great distinctness, but which were so
far disintegrated as to make it impossible to remove them from their
position without their crumbling to fragments. Among the fragments
resulting from the disruption of shale bowlders pieces may be found
which retain portions of the original surface, and upon these stria? may
still be seen. The4 matrix in which the stony material is imbedded is
locally of granite and crystalline schist origin — a sort of arkose. Its
abundance may perhaps be due in part to the decomposition of the
granitic material in the drift itself since its deposition.

High Bridge is about fourteen miles from the moraine at its nearest
point. A few miles farther southwest ward, near Pattenburg, the phe-
nomena of High Bridge are repeated at a slightly greater elevation
But a single point of difference need be mentioned: the bowlder clay
here rests on shale, the surface of which beneath the drift gives evidence
of mechanical disturbance.

Similar occurrences of bowlder clay are known south of Pattenburg to
a distance fully twenty miles south of the moraine. In all these places
the bowldery clay is essentially constant in chemical and physical
character, and whatever may lie the explanation of its existence in one
locality must he the explanation of it in all.

CORRUGATION AND CRUSHING BY ICE. 179

Nor arc the phenomena above referred to restricted to the New Jersey
side of the Delaware. South of South Bethlehem, in Pennsylvania, the
same materials occur several hundred feet above the Lehigh valley.
Finely glaciated bowlders imbedded in clay have been seen at more than
one point south of the Lehigh at distances from the moraine comparable
to those at which occur the Pattenburg and High Bridge deposits al-
ready referred to. In Pennsylvania, as in New Jersey, the material has
a vertical range of several hundred feet.

Direct Evidence of Ice Work. — In the eastern part of New Jersey, near
New Brunswick, some six miles from the moraine in direct line and at
an elevation of 100 feet, there are some recently exposed sections which
show a bowlder-bearing clay with rarely a glaciated bowlder resting on
an irregular surface of Triassie shale. The irregularity is not of such a
character as would be produced by erosion. It bears evidence rather of
mechanical disturbance. In many places the stratification planes of the
shale have been obscured by the crushing of the shale, but in other places,
where the crushing effect has been less, the shale appears to have been
pushed up into folds two to four feet high and with a width about equal
to their height. In some cases these folds have been pushed over to one
side, the bowlder clay wrapping around the inclined folds, lying beneath
as well as above them. In other cases where stratification planes have
been obliterated, or so nearly obliterated as to make their position indis-
tinct, there are other phenomena exhibited scarcely less significant than
those mentioned in determining the origin of the bowlder clay. There
are places for considerable stretches where the material overlying the
shale is essentially composed of red shale crushed to small fragments, or
reduced to clay. This takes the place of the transported material which
overlies the shale elsewhere. In the midst of such masses of broken
shale, strictly local in origin, occasional bowlders of transported material
occur, even down to the surface of the bedded shale. Exactly correspond-
ing phenomena may be observed in many glaciated regions where the
underlying rock is soft, or where a great amount of residuary material
was accumulated on the surface prior to glaciation. It is quite compre-
hensible thai such relations could be brought about by glacial action, but
it is difficult to conceive how such results can be achieved by any other
agency. At one other locality, fifteen miles southwest of New Bruns-
wick, similar phenomena may be seen, though less strikingly developed.

Distribution of the Phenomena. — No determinations have yet been made
as to the southern limit of this bowlder-bearing day. The points in
New Jersey and Pennsylvania mentioned above, however, are not the
southernmost Localities where glaciated material is known to occur.
Striated bowlders have been found hoth hv Mr. Charles E. Peel and the

ISO I!. I). SALISBURY — EXTRA-MORAINIC DRIFT.

writer ;il and near Monmouth Junction, nearly twenty miles from the
moraine at its nearest point and fully forty miles south of the moraine
on the same meridian. Glaciated material has also been found at
Kingston, about halfway between New Brunswick and Trenton. It has
been found in Pennsylvania about three miles west of Trenton, near
Falsingham. The similarity of the surface material of this locality to
glacial drift (till) was first recognized by Professor Smock. Striated
materia] has also been found at Bridgeport (opposite Norristown), Penn-
sylvania, by Mr. Peet and the writer, at least ten miles south of the
parallel of Trenton. As at Falsingham, the striated material is here im-
bedded in clay of such a character that, were the locality known to have
been covered by ice, its reference to till would be fully warranted. This
locality is nearly or quite fifty miles south of the nearest point of the
moraine. Striated material has also been found near Sunbury, Penn-
sylvania, between 25 and 30 miles south of the moraine in this longitude
and at an elevation between 500 feet and 600 feet above the Susquehanna
at that point. In all the localities last mentioned striation is relatively
rare, but some of them have afforded bowlderets as beautifully striated
as those of the Alpine glaciers of to-day. ,

SroXTFICANCE OF THE OBSERVATIONS.

General Bearing. — The foregoing statements give facts selected from a
much larger body of data in the writer's possession concerning the distri-
bution and nature and relations of extra-morainic surface formations. In
the judgment of the writer these facts are sufficient to warrant the conclu-
sion that glaciation extended further southward than the published mo-
raine, both in New Jersey and Pennsylvania.

It is not to be understood that the writer would imply that land-ice
has covered every region where glaciated material is found. The possi-
bility of water transportation of glaciated material beyond the edge of
land-ice is distinctly recognized, but it is not believed that water alone,
or water bearing glacially derived bergs, could produce all the results
which have been observed. Neither the physical and chemical condition
of the material nor its geographic and vertical distribution are consistent
with such an hypothesis.

From the character and relations of this extra-morainic drift, particu-
larly from the degree of its oxidation, disintegration and erosion, it is
confidently believed that it is to he regarded as the equivalent of the
oldest glacial drift of the interior.

Number of Ice Invasions. — The conviction has been growing for some
time in the mind of the writer that the coninion.lv accepted division of

SUBDIVISIONS OF THE ICE PERIOD. 181

the ice period into two epochs may not be final. If this classification
is to undergo modification, it is believed that the change will be in the
direction of greater complexity. Data have heen accumulating for sonic
time past which would seem to be best explained on the basis of three ice
epochs instead of two. Tins suggestion is less of an innovation than it
may at first seem to be. President Chamberlin long since recognized two
distinct episodes in the first glacial epoch, as classified by him, the two
being separated by an interval of milder climate and ice retreat. The
suggestion here made would simply emphasize this division already
recognized. While President Chamberlin has hitherto regarded this in-
terval of mild climate as marking a subordinate interruption of glaciation
determining the division of the earlier ice epoch into episodes, Mr. McGee
has regarded it as marking the greatest interruption of glaciation during
the glacial period, determining the division of the ice period into two
epochs. Mr. McGee's first glacial epoch would therefore correspond to
the first glacial epoch of the classification here suggested, while his sec-
ond glacial epoch would embrace the second and third as here proposed.
On the other hand. President Chamberlin's first epoch embraces the first
two, and his second the third epoch, if the ice period he divided into
three epochs.*

Briefly characterized, the drift representing the ice advance of the first
epoch has no marginal accumulation of the nature of frontal moraines.
Its margin is attenuated. The drift representing the ice advance of the
second epoch, according to the suggestion here made, is limited by mo-
rainal ridges, which are bordered and often covered by loess, loess-loam
and silt deposits, which indicate slack drainage; Avhile the drift of the
third epoch is limited by stronger terminal moraines of more pronounced
topography, in which valley trains and overwash plains of gravel take
their origin. These valley trains of gravel often extend many miles
down the valleys from the moraines, and demonstrate that the attitude
of the Land was such as to determine vigorous drainage. The degree of
erosion, oxidation and disintegration of the drift of the several epochs is
progressively less, from oldest to youngest. The significance of the silt
and loess bordered moraines, as distinct from those bordered by gravel
plains and trains in indicating continental attitudes, was long since
pointed out by President Chamberlin, as was also the significance of the
varying degrees of erosion, decomposition and disintegration of the drift.
In briefly indicating, therefore, the broad divisions of the drift, corre-
sponding to the three epochs suggested, the features noted are in noway

Because oi the importance attaching to hi- opinion <>n this question, I am glad t<> say thai
Presidenl Chamberlin i- very hospitable n> Lhe suggestion here made of :i tripartite division
of tin' glacial period,

\ \ l\ Bom Hoi \m.. \ ni , ::, 1891.

182 R. D. SALISBURY — EXTRA-MORAINIC DRIFT.

new, but were long since recognized by President Chamberlin and have
been made use of by him and his assistants in field determinations.

Correlation of Deposits. — Apart from the inherent interest winch attaches
to the determination of the existence of a first glacial drift south of the
moraine in New Jersey and Pennsylvania, this determination is likely to
prove helpful in another direction.

The extra-morainic glacial drift in northern New Jersey and Pennsyl-
vania affords a definite starting point for determining the relation of the
glacial formations of the north to the coastal plain formations of the
eastern and southeastern United States. It may not he out of place to
add that the conclusion has already been tentatively reached that the
" yellow gravel " formation of Dr. Cook is older than the extra-morainic
drift. If this tentative conclusion shall prove to be correct, and if the
drift he first glacial, then the " yellow gravel " must he preglacial, and
therefore pre-Pleistocene.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 183-186 March 31, 1892

ON THE NORTHWARD AND EASTWARD EXTENSION OF THE
PRE-PLEISTOCENE GRAVELS OF THE MISSISSIPPI BASIN.

BY R. D. SALISBURY.

[Abstract.]

(Presented before the Society August 25, 1891.)

CONTENTS.

Page

Early < )pinion as to the Age of the " Orange Sand " 183

I >iscovery of " Orange Sand " within the I >rift Limits 184

Ancient Gravels replacing Drift 184

Ancient ( travels underlying Drift 184

Relations of the pre-Pleistocene Gravels 185

Early Opinion as to the Age of the "Orange Sand."

In a recent number of the American Journal of Science* President
Chamberlin and myself discussed at sonic length the relationship of cer-
tain gravels in the middle Mississippi basin to the loess and to such other
formations of that region as were demonstrably of Pleistocene age. In
thai article we expressed the conclusion that the gravels in question,
composed mainly of chert and of other silicious impurities from lime-
stone, were of pre-Pleistocene age. The evidence on which this conclusion
was based need not here he repeated. We then believed it adequate to
the conclusion reached, and nothing has subsequently been discovered
by us to weaken the force of the arguments then used or to alter the con-
clusions based upon them.

Since the discussion referred to was published, some additional facts
have come to light which have an important hearing on the question at
issue. A brief note concerning these newer discoveries has already
appeared in the American Journal of Science.!' It Lsthe purpose of this
paper to set forth somewhat more fully the bearings of the data recently

acquired.

*:•,(! series, vol. \li, L891, pp. 3 i9-377.
; id series, vol. xlii, 1801, pp. 262-253.

(18

184 R. D. SALISBURY — EXTENSION OF PKE-PLEISTOCENE GRAVELS.

The attempt was long since made by the writer, under the direction of
President T. ('. Chamberlin, to determine the stratigraphic relationship
between the glacial drift and the "Orange Sand" gravels of southern
Illinois and the contiguous areas of Missouri, Arkansas, Kentucky and
Tennessee. That portion of southern Illinois occupied by the southern
margin of the drift is the area which has been especially studied in the
hope of finding these two formations in contact, and therefore in such
relationship as to determine their relative age. It was known that the
" Orange Sand " gravels * extended northward to within a few miles of
the glacial drift. Their distribution in the northern part of their exten-
sion was known to be much interrupted by erosion, and it was the hope
that certain areas of the gravel might be found as far north as the south-
ern limit of the drift; but up to the present season it had seemed that
the southern gravels failed to reach the drift-covered territory by twenty
or twenty-five miles.

Discovery of "Orange Sand'' within the Drift Limits.

Ancient Gravels replacing Drift. — In May and June of the present sea-
son, what appears to be a small driftless area was found to exist in
Pike and Calhoun counties, Illinois.!" In this area, apparently free from
northern drift, the loess was found to be underlain by an interrupted
bed of gravel of variable thickness, corresponding to the " Orange Sand "
gravels farther southward. The gravel is found mainly on the level up-
lands and on the summits of ridges where erosion has been least. It was
thus determined that the gravel formation hitherto known only south of
the northern drift had a northward extension much beyond the south-
ern border of the ice-sheet; but the stratigraphic relationship of the drift
and of this gravel was not directly shown by the new find, though the
occurrence of the gravel in this situation — in an area completely sur-
rounded by brift — tended strongly to confirm the previous conclusion as
to its pre-Pleistocene age.

Ancient Gravels underlying Drift. — Subsequently the area surrounding
the newly found driftless tract was studied, and in northern Pike, in
Adams, and in Hancock counties gravel identical with that in the drift-
less area of Calhoun and Pike counties was found to exist. In these
counties its position is such as to indicate unequivocally its relationship
to the glacial drift. Wherever it is seen in section in these counties it
constitutes a well defined layer inferior to the till.

* The term " Orange Sand " gravels is here used in its widesl sense, including all thai has been
designated by this term.

f'On the probable existence of a second driftless area in the basin of the Mississippi river."
Read before the Am. Assn. Adv. Sci., Section E, 1891.

RELATIVE ANTIQUITY OP GRAVELS AND DRIFT. 185

South of the drift the gravel is often accompanied by considerable
layers of sand. This sand may be interlaminated with the gravel, par-
ticularly in its lower parts, and often forms its substratum. In like
manner in the counties referred to, far north of the southern boundary
of the drift, considerable beds of sand locally accompany the gravel and
sometimes remain where the gravel lias been entirely removed.

Both the sand and the gravel have yielded of their substance to the
till which overlies them. So generous has been their contribution that
locally the drift is often largely composed of their materials. Where this
is the case deep sections frequently show a remnant of the sand and
gravel beneath the till in undisturbed position. From this relationship
it was at once suggested that the influence of these sands and gravels in
determining the character of the till over the region where they once
existed might be a means of helping to determine the former northern
extension of the gravels and sands. Acting upon this suggestion, the
area farther north was studied, and what are believed to be unmistakable
evidences of gravel corresponding to the formation of the south are found
in the drift as far north as Henderson county and probably as far north
as Rock Island county; but Rock Island county is not far from the
southern border of the northern main driftless area.

Relations of the tre-Pleistocene Gravels.

It will be observed from what has been said that this formation of
gravel regarded as pre-Pleistocene occurs south of the drift, extends north-
ward witb considerable interruptions to the border of the drift, reappears
in the driftless area of Calhoun and Pike counties, passes beneath the
drift north of this area, and may be recognized to the northward either
in positions subjacent to the drift or by its contribution to the drift well
toward the northern driftless area.

Several years since, while studying the driftless tract of southwestern
Wisconsin, the writer had occasion to notice certain gravels which had
been earlier described, but which manifestly had nothing to do with
glacial drift. No satisfactory explanation of their origin had ever been
offered. Similar gravels occur a( certain localities in the driftless south-
easl corner of Minnesota. It is now believed to he possible and even
probable that these gravels in the northern driftless area are to be corre-
lated with those farther southward. If this he true the pre-Pleistocene
( presumably Tertiary I gravels have ;i far greater northerly extension than
has heretofore been known ; and this remains true, though the extension
is less great, whether the gravels of the Wisconsin driftless area are cor-
related with the gravels of the south or not.

L86 R. I). SALISBURY EXTENSION OE ERE-PLEISTOCENE GRAVELS.

Subsequent to my own first determination of the existence of these
gravels above the mouth of the Illinois river it was found that Professor
Worthen had already noted their existence in Hancock* and Pike f
counties and had correlated them, as I think rightly, with similar gravels
farther southward .J

The extension of these pre-Pleistocene gravels northward docs not
appear to be their only one. To the eastward as well they have a greater
extension than has heretofore been known, so far as I am aware. They
have been found in Gallatin county, Illinois, near the Wabash river.
This is the only point in eastern Illinois north of the Big Bay Cache
valley (an old course of the Ohio) where they are known to occur. These
gravels have their easternmost extension, so far as now known, near Tell
City, Perry county, Indiana, where there are very considerable beds
identical in all essential features with the gravels of the Mississippi valley.

In the Ohio valley, as in the Mississippi, gravel which belonged origi-
nally to the same formation has been recognized in the drift and has been
seen in secondary positions many miles east of Tell City. It may, there-
fore, be confidently affirmed that this locality does not represent the
original eastern limit of the formation, although it is many miles east
of any locality north of the Ohio heretofore known to the writer to be
characterized by these gravels.

*Geol. Survey of III., vol. i, 1866, p. 331.
fGeol. Survey of 111., vol. iv, 1870, p. 37.

JiSome years previously similar gravels wore described by McGee from northeastern Iowa (Geol.
Mag., new series, decade ii, vol. vi, pp. 3.",."), 360).

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 187-216, PL. 6; pp. 217-218

THE MANNINGTON OIL FIELD AND THE HISTORY OF ITS

DEVELOPMENT

FOSSIL PLANTS FROM THE PERMIAN BEDS OF TEXAS

I. C. WHITE

ROCHESTER
PUBLISHED I'.v THE SOCIETY

Arm i, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 187-216, pl. 6 April 15, 1892

THE MANNINGTON OIL FIELD AND THE HISTORY OF ITS

DEVELOPMENT.

BY I. C. WHITE.

Read be/on the Society December 29, 1891.)
CONTEXTS.

Page.

The Field is;

Location and general Features 187

Si mrce of the Hydrocarbons 188

The Stratigraphy L89

The Mount Morris Section L89

The Mannington Section 190

The Fail-view Section ]<>1

General Features 192

Development of the "Anticlinal Theory'' 1<;:;

Application of the "Anticlinal Theory " 197

The * >rigin of Petroleum 202

Appendix 204

The "Anticlinal Theory " of natural Gas 204

The Criticisms of the "Anticlinal Theory " of natural Gas 215

The Field.

Location and general Failures. — The Mannington oil field is situated in
Marion county, West Virginia, on the main line of the Baltimore and
Ohio railway. It is an extension of the Mount Morris (Pennsylvania)
field, which begins just north of the West Virginia slate lino and trends
in a belt of varying width southwestward, across Marion and Monongalia
counties to the edge of Harrison county. Dolls run, Pedlars run, Jakes
run, Fairview and Mods run are centers of development along the belt,
which as now defined is from half a mile to three miles wide and about
•".o miles long.

The cross section on the accompanying map folate 6) shows thai the
oil bell in question is found on the western slope of the Indiana anticline,
and is from 1") to -!!' miles distant from the great axis of Chestnut ridge.
The dip is northwestward, and varies from 150 feel per mile al Mount
Morris to 50 feel at Mannington. The belt is thrown westward in southern

\ \\ la i i Gkoi Soi .Am., Voi ".. 1891. (,187)

188 I. C. WHITE — THE MANNINGTOfl OIL FIELD.

Monongalia by the development of a new anticline which elevates the oil
rock into the gas belt along its previous trend, and thus causes the oil
level to veer westward, at the same time reducing the rate of dip and
consequently broadening the oil belt in that region, as shown by the map.

Source of the Hydrocarbons. — The oil is found in the Pocono sandstone
(Vespertine, X, etc. of Rogers) or lowest member of the Carboniferous
system, its geological equivalent being the Logan sandstone of Ohio, the
Shenango and Sharpsville sandstones of Pennsylvania, and the Marshall
group of Michigan. This geological horizon has furnished oil at several
localities in this country : the " Slippery rock " and '' Manifold " oil sands
of Pennsylvania, the " Mecca " sand of Ohio, and the main sand at Burn-
ing springs and Volcano, West Virginia, all belonging to the Pocono beds.
It was from this same horizon that natural gas was obtained in the
Kanawha valley fifty years ago, and there first utilized for manufacturing
purposes. The Warfield gas wells of Kentucky are in this sand, and it
also furnishes oil at many localities in that state, while the asphalt de-
posits (residua of evaporated petroleum) of Alabama occur in the same
series. Hence it will be perceived that this horizon is one which holds
hydrocarbons over a wide area, just like the older Catskill (Venango oil
sands: and upper Chemung beds (Bradford and Warren sands) below.

This oil rock was several years ago dubbed the "Big Injun " sand by.
some facetious driller in Washington county, Pennsylvania, where it is
about 250 feet thick and very hard, thus rendering the progress of the
drill through it quite slow and suggesting the name which it has ever
since maintained in oil parlance, viz, the " Big Injun " sand. It is also
sometimes called the "Manifold" sand, from the farm in Washington
county on which was obtained the only paying well in that county at
this horizon, out of the hundreds and thousands that have been drilled
through it, though the name " Mount Morris " sand is more appropriate,
since it has proven more productive of oil in the Mount Morris-Manning-
ton field than anywhere else.

The oil and gas are not disseminated uniformly through the sand rock
but occur in " pay streaks " at 60 to 135 feet below the top of the Pocono
sandstone, the richest and main horizon being found at 85 to 110 feet.
At about 20 feet in the sand there is a layer which frequently furnishes
a small flow of gas, but has never vet produced any oil. Then at (50 to
75 feet the " first pay " is usually obtained, and at Xo to 110 the " second
pay;" while a " third pay " may be found at 120 to 135 feet. These
" pay streaks " are merely coarser and more open layers of sand in which
the oil, gas, or water, as the case may be, finds a good receptacle.

The texture of this sand is not coarse and pebbly like the ( 'atskill con-
glomerate of the Venango sand group, and hence its oil wells are never
so large as those from the latter beds, but they are on that account the

OUTPUT AND CHARACTER OF OIL.

189

180
300
325
410
420
430
515
525

595
650

US."")

700
710
7::-")

7! 10

830

851 1
930
935
960

170

more lasting. The wells in the >- Mount Morris " or " Big Injun " sand
produce from 5 to 500 barrels daily, after they have been flowing for a
period of thirty days, though some have been known to start off at the
rate of 50 barrels an hour when first struck.

The oil is of a beautiful amber color and compares favorably with the
best of that produced from " white sand " territory. Its gravity is 48° to
50° as the oil issues fresh from the wells, but this usually falls to 45° by
the time it reaches the main pipe line station and starts on its journey
through the great pumps of the National Transit company to tide water
at Philadelphia.

The Stratigraphy.

The Mount Morris Section. — The following record of the Core well num-
ber 2, near Mount Morris, kept by Mr. John Garber, contractor, exhibits
the geological relations of this oil sand to the overlying beds of the Car-
boniferous system in that region :

Permian or Dunkard Creek series : Feet. Feet.

Conductor (clay) , » 21 to 21)

Slate 104 to 125 \

Sandstone, Waynesburg 45 to 170 j

Upper Coal Measures :

Coal, Waynesburg 10 to

Limestone and shales 120 to

Sandstone 25 to

Limestone (Great limestone) 85 to

Black slate 10 to

Coal, Sewickley 10 to

Limestone, Sewickley and Redstone 85 to

Coal, Pittsburg ....." 10 to

Barren Measures or Elk River series :

Slate (eased at 531 feet) 70 to

Sandstone, ( 'onnellsville 55 to

Red shale 35 to

Sandstone 15 to

Red shale 10 to

blue shale 25 to

Sandstone, Morgantown (salt water at 700 to 785 feet I 55 to

blue slate 40 to

Red and blue shale ((Yinoidal limestone horizon ; eaves

badly and causes much trouble in drilling) 20 to

Limestone and hard beds 80 to

Red slate 5 to

Sandstone, Upper Mahoning 25 to

Dark .dale 60 to 1020

Sandstone, Lower Mahoning 30 to L050

b >\\er ( 'oal Measures :

Slate, Lighl gray 60 to 11 b)

Sandstone. Freeporl 80 to ] loo

Dark slate 25 to L215

Limestone, Johnstown 40 to I 25

Dark slate I0to 12

Sandstone, hard 5 to L300

Slate 60 to L360

dOO

! :>•>

>!'■>

310

LOO I. C. WHITE — THE MANNINGTON OIL FIELD.

Pottsville conglomerate :

" Salt sand," part of XII (water at 1,442 feet) 150 to 1510 ]

Slate (cased at 1,515 feet) 10 to 1520 |

Limestone (?) 20 to 1540 -

Slate 10 to 1550

Dark pebbly sand 20 to 1570

Mauch Chunk shale :

Light-colored sandstone 95 to 1665

Limestone, hard 22 to 1687

Red shale 13 to 1700 j- 1 78

Dark slate 45 to 1745

Red shale 3 to 1748

395

Limestone, " Mountain " or " Greenbrier " 56 to 1804 \

" Big Injun " or Mount Morris sand, with oil from 1,890 to > 157

1,912 feet 101 to 1905 J

The Mannington Section. — In the Hamilton test well (number 1) at

Mannington also the record was kept by Mr. Garber, and reads as
follows :

Permian or Dunkard Creek scries : i--,.et. Feet.

Conductor (soil) 15 to 15

Coal. Waynesburg "A" • 1 to 16

Slate . 14 to 30

Blue sand, Waynesburg 35 to <i5

Slate (Waynesburg coal at 78 feet, but not noted) 25 to 90

Upper Coal Measures :

Sandstone, Browntown 30 to 120

Limestone 40 to 160

Slate 35 to 195

Limestone interstratified with thin shales 142 to 337

Slate 8 to 345

( !< >al, Sewicklev 12 to 357

Slate ' 35 to 392

Limestone 48 to 440

Dark slate 11) to 459

Coal, Pittsburg 11 to 470

Barren Measures or Elk River series:

Slate 25 to 495

Limestone, hard 40 to 535

Sandstone, Connellsville 35 to 570

Slate 23 to 593

Sandstone, hard 4 to 51),

Red shale 6 to 603

Variegated shales 87 to 690

Red shale 10 to 700

Limestone (shaly), Crinoidal 45 to 745

Coal, Crinoidal 5 to 750 j 607

Blue slate 25 to 775

Limestone JO to 785

Red shale 13 to 798

Limestone and shales 26 to 824

Sandstone, dark 20 to 844

Slate, dark 31 to 875

Sandstone, Upper Mahoning (some gas and water) 45 to 920

Slate, gray (caving material) 65 to 985

Sandstone, Lower Mahoning 92 to 1077

SECTIONS DEVELOPED BY BORING.

191

Lower Coal Measures:

Slate

Sandstone, hard

Sandy shales and slate

Trace of coal (Kittanning Upper coal ?)

Black slate

Sandstone, very hard

Coal and slate, Lower Kittanning

Limestone and slate

Hard sandy shales, and slate

Pottsville conglomerate :

White pebbly sandstone ("salt sand;" big flow of salt

water at 1,385 feet)

Dark slate

Dark pebbly sandstone

Sandy beds

Trace of coal, base of number Xli

Mauch Chunk shale :

Light-colored slate

Red shale

Limestone, slaty (cased at 1,680 feet)

Red slate

93 to 1170
15 to 1185
45 to 1 230

20 to 1250 \-
27 to 1277
17 to 1294

21 to 1315
55 to 1370 ,

293

17 to 1487

31 to 1518

15 to 1533

37 to 1570

200

30 to 1600
78 to 1678 i
28 to 1706 |
5 to 1711 J

141

Limestone, " Mountain " or " Greenbrier " 92 to 1803

"Big Injun" (Mount Morris) oil sand, composed of-

(a) Gray sand (gas at 1,815 feet) 37

(b) Cream-colored limestone 17

(d) Gray sand with oil at base 8

(e) Bluish gray sand ( with more oil at 1,885 feet and

some water at 1,910 feet)

72 to 1875 r 219

55 to 1930

The bottom of the Wayneshurg coal should have been found in this
well at about 78 feet from the surface.

The Fairview Section. — Near Fairview, 10 miles northeast of Manning-
ton, the measures exhibit the following structure, as shown by the record
of the Brice Wallace well number 1, given me by Mr. John Worthington,
of the South Penn oil company:

Feet.

( ionductor 12 to

Gray slate 30 to

( !oal, Waynesburg "A" 4 tc

Sandstone, Waynesburg 87 t<

Slate ' 4 t<

I rpper ( loal Measures :

Coal, Waynesburg 7 t<

Slate ."> t<

White sandstone, Browntown 4iu<

( loal, Little Waynesburg (it.

I limestone 39 t<

Slate and sandy beds 50 1

Limestone

slate and limestone

White sandstone, Sew ickley

( loal, Sewicklev

Slate, BOfl '

Limestone, hard

Slate

Coal, I'ii tsburg

16 t<

no t<

40 t(

Id t<

25 t-
35 t<
30 t.
N t(

133

137

141
L49
189
195
234
28 I
320
380
420
430
l.v,

490
521 1
534

Feel

137

.",'.ni

L92

I. C. WHITIv — THE MANNINGTON "II, FIELD.

Barren Measures or Elk River series:

Slate, white 31 to

Limestone 40 to

Slate, white 15 to

Red shale 25 to

Light sandy beds 50 to

Red and gray .shales 1<>"> t < >

Limestone 15 to

Red and gray shales 40 to

Sandstone 25 to

Coal i Masontown) and white slate 30 to

Sandstone, hard, Upper Mahoning 35 to

Slate, dark 45 to

Sandstone, Lower Mahoning 40 to

Lower (Vial Measures:

Coal (Upper Freeport ) and slate 20 to

1 >ark slate and sandstone 161 I t( i

Sandstone 30 to

Slate and sandy beds (50 to

Pottsville conglomerate :

Sandstone (top of XII, Homewood) 50 to

Slate and sandy beds 69 to

•• Salt sand " (salt water at 1,525 feet) 136 to

Mauch Chunk shale :

Red beds 140 to

Slate, dark 25 to

565

605

620

045

695

860

875 ;

915

1140

'.(70

1005

1050

1000

1110]
1270 !
1300
1360

1410)
1479 -
1615 )

1 755 i
1780 i

Limestone, " Mountain " or " Greenbrier" 70 to 1850

"Big Injun" (Mount Morris) sand, composed of —

(a) I > ray sand 65

(b) Limestone 7

(>1) Sand, gray (heavy gas; "second and third 142 to 1992

pays") 30

i i Sandstone (oil show in bottom) 13

(/) Sand 7

Slate to bottom of well 5 to 1999

556

270

255

10.-)

519

General Features. — By reference to the details of these records it will be
observed that the Upper Coal Measures ' XV i, Barren Measures ( XIV |,
Lower Coal Measures (XIII), Pottsville conglomerate (XII), and the
Mauch Chunk shale and Mountain limestone (XI) are all well repre-
sented, and that the latter series rests immediately on top of the Mount
Morris oil sand, which corresponds to formation X of Rogers, or the
Pocono sandstone of Lesley.

Another interesting fact will also ho observed, viz, that the interval
from the Waynesburg coal to the tup of the oil sand is 1,624 feet at Mount
Morris, 1,706 feet at Fairview, and 1,725 feet at Mannington. thus show-
ing a progressive increase in this interval from Mount Morris to Manning-
ton of about 100 feet. This condition of affairs, as will he seen hereafter.
plays a very important part in determining the exact course of the Mount
Morris oil held when traced south westward.

Development of the "Anticlinal Theory."

The Mannington oil Held was developed by myself and associates, and
as its location was made from purely scientific deductions illustrative of
certain theories concerning oil and gas accumulation which I have taught
for several years, a brief history of these theories and their application
in the discovery of the Mannington field may not be without interest to
geologists ; and this must excuse much that is personal to myself in con-
nection therewith.

As is well known, it was formerly a popular saving among practical
oil men that " Geology has never filled an oil tank ; " and to such a low
estate had oil geology fallen that a prominent producer of oil and gas,
disgusted with geology and geologists, was once heard remark that if he
wanted to make sure of a dry hole he would employ a geologist to select
the location. It has been my pleasant task during the last eight years
to assist in removing this stigma from our profession, so that with the
able and valuable assistance of Ohio's distinguished geologist, Professor
Orton, Dr. Phinney, of Indiana, and others the battle against popular as
well as scientific prejudice has been fought and won and this longstand-
ing reproach to geology in great part removed. The battle was opened
by the publication of a paper in "Science" of June 26, 1885, entitled
" The Geology of Natural Gas," by I. C. White.*

As gei >logist sarea ware, Hunt, Andrews, M inshall. Xewl >erry, and Steven-
son had all previously recognized some of the factors of oil and gas accumu-
lation, but the paper in question contained the first clear exposition of
what has been termed the "anticlinal theory" of oil and gas. Astherein
stated, I was led to the discovery of the laws of gas, oil and water accu-
mulation through a remark by Mr. William A. Earseman, a practical oil
operator of many years' experience, and now general superintendent of
the South Penn oil company, one of the Standard oil company's most
successful concerns. Mr. Earseman believed, in spite of the disrepute
under which geology rested with practical oil and gas operators, thai it
could, if rightly applied, render them valuable service. 1 le believed this
so thoroughly that he induced Captain -I. .1. Vandergrift, president <>!' the
Forest nil company, to engage my services in June, L883, lor a general
study and investigation of the subject, the results of which were embodied
in the paper to which reference has been mad.'. The propositions formu-
lated then for the first time in any scientific publication provoked a dis-
cussion of the general Bubject of oil and gas accumulation, and as these
letters and papers of mine are scattered through several journals which

* Reprinted in tin Appendix, ante, pp. 2tM 2()G.

194 I. C. WHITE — THE MANNINGTON OIL FIELD.

geologists generally have not read, and as they mark a new and impor-
tant epoch in the history of gas and oil geology, and are therefore worthy
of being preserved to geological literature in a more permanent form than
they have heretofore had, I shall append to this paper a fairly complete
history of that discussion so far as my own part in it was concerned, the
same being compiled from the pages of Science, The Petroleum Age and
the American Manufacturer, in which journals my contributions to this
subject were originally published.

The essential principles involved in the paper and discussions referred
to, as embodied in the " anticlinal theory," have been verv forcibly and
graphically set forth by Professor Edward Orton, whose philosophic mind
and skillful hand have grappled with and raveled so many tangled
threads of geologic history. Grasping at once the truth of the " anticlinal
theory," he applied its principles in a striking and beautiful way to the
explanation of the oil and gas deposits of Ohio. Expressed in his words,
relief or structure is the essential element in the accumulation of large
quantities of either oil or gas, for if the rocks lie nearly horizontal over a
wide area we find, when we bore through them, "A little oil, a little gas.
a little water, a little of everything, and not much of anything; " while
if the rock reservoirs be tilted considerably, so that the small quantities
of oil, gas, and water in all sedimentary beds can rearrange themselves
within the rocks in the order of their specific gravities, then and then
only can commercial quantities of each accumulate, provided the reser-
voir and cover are good. The anticlinal waves which traverse the great
Appalachian plateau westward from the Alleghanies and practically
parallel to these mountains present just such relief as the theory requires
in the New York, Pennsylvania, southern Ohio, and West Virginia oil
and gas fields, while the more ancient flexures in northern Ohio and In-
diana account for the large accumulations of oil and gas in the Trenton
limestone of those states. The Florence (Colorado) and other oil fields
in the far western states and territories have this tilted rock structure,
and the same relief is plain in the Canadian oil and gas fields, according
to Selwyn ; while Tschernyschew, Sjogren, and other geologists who have
studied the foreign oil fields, report an identical geological structure there.

This theory, so simple and consonant with well known physical laws,
as well as so harmonious with the facts of geology, was heartily welcomed
by most of the oil and gas operators, and by nearly all geologists that
have given any thought to the matter, as a satisfactory solution of the
geologic problem connected with oil and gas accumulation. A few have
attempted to relegate the great principle of relief to a subordinate posi-
tion, but the facts have pointed so conclusively in the other direction
that opposition has been silenced at least, whether convinced or other-
wise.

TEST OF THE ANTICLINAL THEORY. L95

Guided by this theory I located in 1884 the important gas and oil
field near Washington, Pennsylvania; also the Grapevine gas field along
that great arch of the same name in Westmoreland county ; and the Belle
Vernon field on the Monongahela river. On the same theory I located
and mapped out, for Mr. J. M. Guffey, the celebrated Taylortown oil
field of Washington county months before the drill demonstrated the
truth of my conclusions. And right here on this Mannington-Mount
Morris belt a derrick was built to bore for oil on one of my locations at
Fairview more than five years before the drill finally proved that my loca-
tion was immediately over one of the richest pools of oil in the country,
and before the drill had shown that there was any oil in this portion of
West Virginia. These are only a few of the positive fruits of the theory
to which we can point ; the negative results in condemning immense
areas for both oil and gas being even more important in preventing un-
necessary expenditure and waste of capital where a search for either gas
or oil would have certainly been in vain.

An important corollary, drawn from the " anticlinal theory " of gas and
oil, and announced as probably true in my article in The Petroleum Age
for March, 1886, was that the pressure under which the oil and gas in
any rock or field are found is of artesian origin ; or in other words that
the initial pressure in any oil or gas field is measured by the pressure of
a column of water equal in height to that which rises from the same n >ck
when water is struck instead of oil or gas. This was announced as the
most probable theory in the paper referred to, and Professor Orton has
since* demonstrated the theory to be true in Ohio with reference to the
gas pressures in the Trenton limestone.

The problem of proving that the oil and gas pressures found in the
various sands of Pennsylvania and West Virginia are due to artesian
pressure is not so simple as in Ohio, since the one rock there emerges
from the earth at the level of lake Superior, while the several sand hori-
zons of West Virginia and Pennsylvania come up in many regions of the
country from the base of the Alleghanies westward to the Ohio river ami
northward to lake Erie, so that one can never he certain as to the exact
datum plane from which to measure the top of the water column which
gives origin to pressure; and therefore while the observations prove the
general truth of the theory of artesian pressure for the •"white sand"
rocks of Pennsylvania and Wot Virginia, they are not so complete and
demonstrative as in Ohio'ahd Indiana.

The gradual increase of pressure with depth is strikingly shown in Pie
following scries :

I. ! Soi lm., vol i. 1889, pp. 87 'I

X X \ I l',i i i Iimi Soi \ * Vol I 1801

190 I. C. WHITK — THE MANNINGTON OIL FIELD.

Feet below Lbs. per

/"'■ . sq. in.

Gas in Pottsville conglomerate at Mannington 200-300 350-400

(las in Mount Morris sand at Mount Morris and Mannington. 700 500-550

Gas in Mount Morris sand at Blacksville 800 600 4-

( ras in Mount Morris sand at Harrisville (West Virginia). . . . 1,000 680 4-

Gas in Gordon sand near Pittsburg 1,000 800 4-

Gas in < rordon sand near Waynesburg 2,000 1,300 +

The same story is told by any other set of observations, viz, that for any
particular stratum the amount of pressure its gas develops is directly
proportional to its depth in about the same ratio which a column of
water increases pressure with increasing length.

Since the column of salt water never rises to the surface through south-
western Pennsylvania and West Virginia, and since it is almost impossi-
ble to get the oil drillers to make accurate measurements down to the top
of the water in any particular case, exact calculations as to what the
theoretical pressure should be have not been made, though from close
estimates by cable measurement of the height of the column of water it
is known that the observed pressure in all of the "white sand " oil and
gas rocks of West Virginia and southwestern Pennsylvania corresponds
very closely with what it should be on the hypothesis of artesian origin.
Hence these facts have precluded any other interpretation, and this origin
for the gas and oil pressure has entered into all of my reasoning upon
these problems.

I am aware that Professor Lesley * finds (for himself) an argument for
the '; expansion theory " of gas pressure in the gradual decline of the gas
pressure at Murraysville and Grapeville; but he overlooks some very
simple truths. During a great lire in a town supplied with water by
elevated reservoirs (artesian pressure), when a dozen fire plugs are open
and running under full headway, the pressure in all the street mains is
greatly reduced, and yet the height of the column of water (reservoir)
remains the same, and the original pressure will return when the fire is
over (the water plugs being closed). Also in the distribution of illumi-
nating gas, the pressure rapidly decreases soon after dark, when so many
exits for the gas have been opened (gas jets lighted), though the pressure
remains the same at the gas-holders, or has even been increased. The
underground tankage of gas is an exactly paraded case to that of water
or gas above ground, with the exception that freedom of movement must
be infinitely greater above than below ground, on account of the capillary
nature of the underground conduits; and hence a priori we should ex-
pect that the opening of several exits for the escape of the subterranean
gases would be more marked in decreasing the pressure upon such con-

*Proe. Am. Phil. Soc, vol, xxix, 1891, p. 10,

NATURE OF GAS PRESSURE. 197

duits. But if it were possible to close up all of these exits (gas wells)
there can belittle doubt that the original pressure would finally return.
( >f course in such a ease the water would crowd into the rock and en-
croach upon space hitherto occupied by gas until it had compressed the
remaining gas into a narrower compass and restored its original pressure.

Application of the "Anticlinal Theory."

This question of the cause of gas pressure is of more importance in

connection with the geology of oil than might at first thought appear, as
will be subsequently shown. It was largely upon this theory of the
origin of gas pressure that I concluded that the Mount Morris oil belt
would, when traced south west ward, cross the Baltimore and Ohio rail-
way near Mannington, 25 miles in advance of any oil developments at
the time the prediction was made. My working hypothesis was that
since the gas pressure is due to a column of water, and since this must
he practically the same for any limited area where the rock lies at the
same depth below sea level, the oil deposit in this particular rock must
extend across the country along the strike of the beds, in a pool com-
parable to the surface of a lake or a chain of small lakes, if the rock reser-
voir should not he equally porous everywhere along the strike. Hence,
if my theory is true, it would only be necessary to follow the strike of
any particular coal bed, limestone, or other stratum outcropping where
the oil was actually developed in order to trace the course of the oil belt
upon the surface, and thus to determine with approximate accuracy,
many miles in advance of the drill, the location and width of such possi-
ble oil territory. Very fortunately for my purpose, two persistent coals.
tin- Waynesburg and the Washington beds, cropped to the surface at
Mount Morris, the first well finished there by Mr. E. M. Hukill, in Octo-
ber, 1886, stalling immediately on top of the Waynesburg scam.

My firsl work was to determine the tide elevation of these coal beds,
especially the Waynesburg, with reference to oil, gas and salt water as
developed by the Mount Morris borings. For this purpose one of my
associates. Profess >r T. M. Jackson, then professor of civil engineering at
the West Virginia university, ran a line of levels from the Monongahela
river (using a Baltimore and Ohio railway datum) out to the oil held,
and made a complete survey and map of the twenty or more wells that
hail been drilled nt that time i .la unary. L889) in and about the village of
Mount Morris. He also obtained the elevations of the coal beds a1 every
possible point. From the data thus acquired it was learned that wher-
r t he Waynesburg coal lias an elevation of 950 feet above tide. -a-, and
not oil, was found, and that where it had dipped down belov> 870 feel
salt water was a certainty in the Mount Morris region at least, A- :

L98 I. C. WHITE THE MANNINGTON OIL FIELD.

Washington coal is 155 feet above the Waynesburg bed, the gas and salt-
water limits were found to be 1,105 and 1.025 feet above tide respectively,
when referred to the Washington bed as a datum line.

With these facts in hand, it was only a question of correct identifica-
tion, or tracing of coal beds, and a simple matter of leveling, in order to
follow the strike of the surface rocks at least, for a hundred miles or more.
But the query arose to me, " Suppose the surface rocks do not lie parallel
to the oil sand, then where will the oil belt be found?" The interval
between these coal beds and the oil sand might either thin awav consid-
erably or thicken up an equal amount in passing southward from Mount
Morris. ( If course, if either of these things should happen, the strike of
the oil sand would not run with the strike of the surface rocks, but would
gradually veer away from the latter either eastward or westward, depend-
ing upon whether the intervening measures should thicken up or thin
away. To meet any such possible contingencies, the territory within
which it was considered possible for oil to exist was gradually widened
southward, and at Mannington extended eastward to where the Waynes-
burg coal had an elevation of 1.025 feet instead of 950 (the eastern limit
of oil at Mount Morris), and carried westward to where it had an eleva-
tion of 800 instead of 870 feet (the western limit of oil at the north).

In following the strike line from Mount Morris to Mannington its direc-
tion was found to vary greatly. For the first five or six miles between
Mount Morris and Dolls run the strike was about S. 30° W. : hut toward
the head of Dolls run, the line turned rapidly westward, making a great
curve or elbow and running westward past the village of Fairview, from
which, with many curves and sinuosities, it crossed successively Plum
run. Mods run and Buffalo creek at Mannington. on a general course of
S. 45° W., but varying from this 10° to 15° either way in certain local-
ities. The strike line carried on southward from Mannington passed
into Harrison county through the villages of Pleasantville and Grange-
ville.

This course which I thus mapped out for the extension of the Mount
Morris oil belt was so crooked and passed so much farther westward than
the practical oil men had considered possible that my geological line, or
hypothetical belt, furnished occasion for many jokes and gibes at my ex-
pense among the oil fraternity : and it was with the greatest difficulty and
only by liberal gifts of supposed oil territory that I could induce any of
them to risk their money on a purely geological theory. Finally, how-
ever, a contract to drill a test well in the vicinity of Mannington was en-
tered into in the spring of 1889 with Mr. A. J. Montgomery, of Washing-
ton. Pennsylvania, a gentleman who had given considerable thought to
geology. As this was to be a crucial test of my theory, the proper Loca-

DIFFICULTIES BESETTING PREVISION. l(.»'-»

tion for the test, 20 miles distant from any producing oil well, gave me no
Little concern, since it' the well should prove a failure oil geology would
receive a fatal blow, in the eyes of practical oil men, while if successful
their confidence in geology would lie greatly increased and strengthened.

The problem I had to solve was, whether the interval between the
surface rocks and the oil sand would remain the same as at Mount
Morris, or whether it would either thicken or thin ; since, upon my theory,
if I made a location at Mannington where the Waynesburg coal had an
elevation of 900 feci ;il>ove tide, and the interval from it to the oil sand
remained the s.ime (1,625 feet) as ;it Mount Morris, then if the oil rock
proved open and porous a fair oil well should he found; while if, on
the other hand, tins interval should thin away to, say, 1,575 feet, then
gas would be found, and if it should thicken up to 1,675 feet, salt water
would he obtained, and tins especially would be fatal to my theory, for
the practical oil men were predicting that Mannington was several miles
too far westward, ami hence was in salt water territory. In the absence
of any evidence bearing upon the subject, and rather in opposition to a
general geological fact, viz, that the sedimentary beds thin away rapidly
westward from the Alleghanies, I made up my mind to take no chances
on salt water in this, the first test well, and in finally determining the
location, placed it where the Waynesburg coal had an altitude of 970
feel and the Washington about 1,125 feet. Such a location at Mount
Morris would have been in the gas belt by an elevation of 20 to 25 feet
to spare.

A.s the drill progressed it was found that the intervening rocks were
thickening instead of thinning when compared with the Mount Morris
column, and when the top of the oil sand ("L Big Injun") was finally
struck, the interval from it to the Waynesburg coal measured exactly
1,725 feet instead of 1,625, as at Mount Morris. Finally, on October 11,
L889, the drill penetrated the oil-bearing zone of this sand, and was im-
mediately followed by a -copious showing of oil. the result beingthal my
theory was at once raised from the domain of conjecture to that of demon-
strated fact. Thus a greal victory was won for geology, since il taught
the practical oil men once for all that they could not afford to disregard
geological truths in their search for oil deposits.

This thickening of the interval between the Waynesburg coal and the
oil sand to the extern1 of 100 feet, in the distance of 25 miles from Mount
Morris to Mannington, proved to have exactly the effeel thai I anticipated,
i. «.. it caused the oil bell to veer eastward until (as may he <i^-n by the
accompanying map, plate 6) it gradually encroaches upon the territory
occupied by the gas bell in the vicinity of .Mount Morris: so thai the
western edge of the oil bell at Mannington is found where the Waynes-

200 I. C. WHITE — THE MANNINGTON OIL FIELD.

burg coal lias an altitude of 950 feet above tide, which is where the eastern
cduc occurs at Mount Morris, and the gas belt begins ; and hence, had
the first location at Mannington been made without taking into account
a possible thickening, the well would have been too far westward, and a
dry hole or salt water would have been the certain result. The amount
of this eastward shifting of the strike of the oil sand compared with the
strike of the surface rocks between Mount Morris and Mannington is
something more than half a mile, and is exhibited to the eye on the ac-
companying map by following the 1,000 feet (deration of the Waynesburg
coal between the two points. The black line representing the strike of
this bed at that elevation will be seen to lie east of the oil belt at Mount
Morris, hut at Mannington the oil belt is found with its eastern edge just
east of this 1.0(H) feet strike line.

Since this Mannington test well was drilled, about 200 others have
been sunk along the belt, as previously defined by me. between Mount
Morris and Mannington; and the correctness of my theoretical work has
been demonstrated by the drill in opening up along this belt through
Marion and Monongalia counties one of the largest and most valuable
oil fields in the country. Fewer dry holes have been found along this
belt than on any other oil belt known to me, not more than 5 per cent
of the wells drilled within the defined limits proving totally dry.

It is notclaimed that this same chain of reasoning can be applied with
like successful results to the discovery and development of every great
oil field that yet lies hidden below the surface of the Appalachian plateau.
but it is believed that a correct understanding and appreciation of the
principles involved and used in the discovery of the Mannington oilfield
cannot fail to prove most useful and helpful to both operator and geolo-
gist in limiting the expensive exploration of the drill to regions where
the geological structure would indicate favorable locations for oil deposits.
Of course no sedimentary bed can extend indefinitely in any direction,
or even for considerable distances, without undergoing a change in the
character of its constituent elements. The individual particles of which
it is composed must vary in size, and the cementing material, or lack of
it, must be an ever-changing quantity. For these reasons any oil rock
must be quite variable in porosity, and hence its productiveness cannot
be a constant amount. Where the oil sand is a mere bed of coarse gravel
or pebbles like that in the famous McDonald region of Washington
county. Pennsylvania, or in the great Russian oil field, then the produc-
tion of an oil well seems to be limited only by the size of the bore hole;
while, on the contrary, the producing rock may become so close and com-
pact within a few feet from a huge producer as to be practically barren
of oil. This fact was strikingly illustrated recently at McDonald, Penn-

CONDITIONS AFFECTING OIL ACCUMULATION. 201

sylvania, since at the very time the famous Mevey well number 1 was
gushing oil at the rate of 15,000 barrels daily, another well was drilled
through the same " Fifth sand," only 300 feet distant, and proved to be
practically dry — the character of the producing rock having undergone
a great change and become so close-grained within such a short distance
that it could not hold oil in paying quantity. If such changes as this
can happen in the character of an oil rock reservoir within a few feet,
much more would we expect such changes within a few miles ; and thus
it happens that although there appears to be a continuous deposit of oil
in the Mount Morris sand, from the Pennsylvania line southward to
Mannington, and for at least six miles beyond, yet the productiveness of
the rock is not everywhere the same, because the character of the sand
(reservoir) is not constant. This condition of affairs tends to concentrate
the richest territory into pools of greater or less extent which are sep-
arated from each other by territory that is "spotted" or less productive.

When this tendency to change in the character of the sand or reservoir
is carried so far as to render the rock impermeable to gas, oil or water
for a considerable distance, then any oil belt must come to an end, and
we need not expect it to set in again on the same strike of the rocks
(though that is possible), but rather when the same stratum become-
again productive it will be found at a lower or higher level and on a
different strike line, so that in this way we may have several parallel
belts of oil in the same stratum, and occupying different levels with
reference to their tidal elevation. Thus, there are numerous productive
belts of the old Third Venango oil sand from Titusville, where it lies
several hundred feet above tide, down to the southwestern corner of
Pennsylvania, where it is 2,000 feet Inline tide. Hence the principles
illustrated in this paper have a local as well as a general application —
local, to enable the operator to follow the course of the oil belt when
discovered; and general, to enable him to limit his search for oil terri-
tory to the localities where the geological structure is favorable.

An effort has been made to find oil on the Mount Morris-Mannington
belt in Harrison, Doddridge and Gilmer counties southwest of Marion:
but the oil rock has changed its character completely along the strike of
this helt, becoming slaty and changing to Limestone; so that although some
oil and gas have keen found in this stratum in both Doddridge and <lil-
mer counties, 50 miles from Mannington, the rock is too close-grained to
hold oil in merchantable quantity. Nevertheless, its presence in small
quantity at the righl geological and tidal elevation at distances along the
Btrike so far away from Mannington as Big Isaac in Doddridge county
and Tannersville in Gilmer demonstrates the correctness of the structural
theory.

202 I. C. WHITE — THE MANNINGTON OIL FIELD.

Just where the Mannington licit will end toward the southwest is, as
yet, uncertain. Oil has been developed along it to within one mile of
the Harrison county line, but in my opinion the belt will end not far
from the latter point, since at the farthest well in advance (Blaker num-
ber 1) the sand is becoming limy and much split up with slate.

It is quite probable that in passing westward from this non-productive
region clown the dip of the rocks through Harrison, Gilmer and Dodd-
ridge counties the sand may improve in quality, and another belt on a
different strike may be found, since there is a dip of about 300 to 400 feet
before we come down to the bottom of the geological slope and reach the
floor of the Appalachian basin*

The lower group, or Venango oil sand, has not yet produced oil in
any of the half dozen wells drilled through these sands along the Mount
Morris-Mannington belt, but some gas has been found in Marion and
Harrison counties and quite a large flow in Doddridge county; so that
there can hardly be any doubt that when the proper search is made in
these sands further down the slope of the rocks than in the few trial
borings already made, oil will be developed in large quantity, just as
certainly as the drill shall rind a good, porous sand reservoir in this
series of deposits, since the group of beds making up the Venango series
is still present in Monongalia, Marion, Harrison and Doddridge counties,
at least, and of about the same thickness and structure as in Washington
and Greene counties. Pennsylvania,

The Origin of Petroleum.

The geological structure in the Mount Morris-Mannington field is so
plainly connected with the accumulation of the oil deposits that consid-
erable light is thrown upon the much mooted problem as to the genesis
of petroleum.

The tias is on one side of a long slope of sand, with salt water on the
other and the oil between. Did the petroleum in this Mount Morris sand
come up from below and simply stop in the sand as a reservoir because it
could not escape to the surface, or did it originate in the sand rock itself?
The rock is an ancient sea-beach or shallow water deposit, and where
exposed at many localities in the country contains marine shells, racoids,
and frequently land plants in such quantity as to form thin coal seams,
which have even been found by the drill in regions where this rock is
barren of oil; so that there was evidently no lack of organic matter in
the original deposition of the rock. When the drill descends below this
stratum a succession of gray and red shales, with other sand rocks, occurs

*Siin-,- tli.' reading <>i this paper .-i promising oil well lias been drilled ;it Center Point, Doddridge
eouniy, several mil'- west of the Mannington strike line

CONVERSION OF ORGANIC MATTER INTO OIL. 20

in the next 1,000 feet, there being but little bituminous slate in thai
interval, and probably none for an interval of 3,000 feet more, or until

the horizon of the Marcellus slate of the Hamilton series is reached.

Does it appear probable that this petroleum has ascended through
nearly a mile of close-grained slates and sandstones, and simply stopped
on its upward course at the horizon in which we find it? I think not :
but rather that the organic matter deposited with and in the sandstone-
has been converted into petroleum and gas within the rock itself, and
that the tilting of the beds has permitted the small quantities of water,
oil and gas in all the porous portions of the rock to rearrange themselves
in the order of their several specifie gravities under the artesian pressure
to which the rock is subjected, so that merchantable quantities of each
have been accumulated. This seems to he the more probable origin of
the Mount Morris-Mannington oil pool, at least, though of course the
particles of oil, gas and water would rearrange themselves in the manne:
found however they might have come into their present reservoirs.

X W'l I C. i \m . \ ..i I ISSl,

APPENDIX.

THE "ANTICLINAL THEORY" OF NATURAL GAS.*

BY I.C. WHITE, OF THE U. S. GEOLOGK \L SURVEY.

At the request of the editor of this paper the writer has consented to arrange
an article f'<>r publication on the above subject. As many of the readers will
perceive, it consists principally of what lias already been published by me in other
journals, but here brought together and condensed into one paper for the con-
venience of those interested in the subject.

The " anticlinal theory " of gas is not entirely new, since both Dr. Newberry and
Dr. Stevenson long ago recognized disturbanct in tin rocks as a factor in the occur-
rence of oil (and consequently of gas).

Also, Mr. F. W. Minshall, an oil operator of many years1 experience, had, it
seems (from a recent letter in The Petroleum Agi I, several years since, recognized
the connection between anticlinal structures and large deposits of natural gas, and
it is quite probable that the same conclusion has been formulated in the minds of
many other oil operators from the results of their practical experience in drilling;
hut so far as the writer knows. Mr. William A. Earseman was the first person who
proposed to test the theory practically by locating trial borings for gas on the
crests of anticlinal folds.

The subject was first brought prominently to the attention of geologists and
others interested in natural gas by a short paper from the writer published in
Science of June 26, 1885, and as the statements therein contained embrace the
"anticlinal theory " as held by its friends and promulgators, it is here republished
in full, in order that its claims may not be misrepresented. The paper in question
read as follows :

"The recent introduction of natural gas into general use as a source of heat for
industrial and domestic purposes has raised it from the rank of a mere curiosity
to one of the earth's most valuable treasures.

"To the reader unacquainted with- the great change natural gas has effected in
all industries where it can lie obtained, the following quotation from an article in
Macmillan's Magazim for January, written by Mr. Andrew Carnegie, the chief iron
master of Pittsburg, will be a revelation : ' In the manufacture of glass, of which
there is an immense quantity made in Pittsburg, I am informed that gas is worth
much more than the cost of coal and its handling, because it improves the
quality of the product. One firm in Pittsburg is already making plate glass of the
largest sizes, equal to the best imported French -lass, and is enabled to do so by
this fuel. In the manufacture of iron, ami especially in that of steel, the quality
is also improved by the pure new fuel. In our steel rail mills we have not used a
pound of coal for more than a year, nor in our iron mills for nearly the same
period. The change is a startling one. Where we formerly had 90 firemen at
work in one boiler-house, and were using 4(H) tons of coal per day, a visitor now

* Reprinted from the "Natural Gas Supplement" to the 1 Manufacture; for April, 188G, pp.

11-13.

(204)

ENUNCIATION OF THE ANTICLINAL THEORY. 205

Walks along the long row of boilers and sees but one man in attendance. The
house being whitewashed, not a sign of the dirty fuel of former days is to be
seen : nor do the stacks emit smoke. In the Union iron mills our puddlers have
whitewashed the coal-bunkers belonging to their furnaces. Most of theprincipal
iron and glass establishments in the city are today either using this Lias as fuel or
making preparations to do so. The cost of coal is not only saved, hut the great
cost of tiring and handling it ; while the repairs to boilers and grate-bars are much
Less.'

"This new fuel, which bids fair to replace coal almost entirely in many of our
chief industrial centers, has not received that attention from the geologist which
its importance demands. So far as the writer is aware, nothing has been pub-
lished on the subject which would prove of any value to those engaged in pros-
pecting for natural gas, and it is the existence of this blank in geological literature
that has suggested the present article.

"Practically all the large gas wells struck before L882 were accidentally dis-
covered in boring for oil ; but when the great value of natural gas as fuel became
generally recognized, an eager search began for it at Pittsburg, Wheeling and
many other manufacturing centers.

"The first explorers assumed that gas could be obtained at one point as well as
at another, provided the earth be penetrated to a depth sufficiently great ; audit
has required the expenditure of several hundred thousand dollars in useless drill-
ing to convince capitalists of this fallacy, which even yet obtains general credence
among those not interested in successful gas companies.

"The writer's study of this subject began in June, 1883, when he was employed
by Pittsburg parties to make a general investigation of the natural gas question
with the special object of determining whether or not it was possible to predict
the presence or absence of gas from geological structure. In the prosecution of
this work I was aided by a suggestion from Mr. William A. Earseman, of Alle-
gheny, Pennsylvania, an oil operator of many years' experience, who had noticed
that the principal gas wells then known in western Pennsylvania were situated
close to where anticlinal axes were drawn on the geological maps. From this he
inferred there must be some connection between the gas wells and the anticlines.
After visiting all the greal gas wells that had been struck in western Pennsylvania
and Wot Virginia, and carefully examining the geological surroundings of each, I
found that every one of them was situated either directly on or near the crown
of an anticlinal axis, while wells that had been bored in the synclines on either
side furnished little or no gas, bu1 in many cases large quantities of sail water.
Further observation showed that the gas wells were confined to a narrow belt, only

one-fourth to one mile wide, along the Crests of the anticlinal folds. These facts
seemed to connect gas territory unmistakably with the disturbance in the rocks
caused by their upheaval into arches, bu1 the crucial test was yet to be made in
the actual location of good gas territory 0:1 this theory. During the last two
years ] have, submitted il to all manner of tests, both in locating and condemning
gas territory, and the general result bas been to confirm tin' anticlinal theory
beyond a reasonable doubl .

■• Put while we can state with confidence thai all greal g is wells are found on the
anticlinal axe.-, the converse of this i< not 1 rue. viz, that <//•■"/ gas wells may lie
found on all anticlinals. In a theory of this kind, the limitations become quite as
i in porta ni as or even more so than the theon itself; and lie nee I have given con-
siderable thought to 1 hi.- side of the question, having formulated them into three

206 I. C. WHITE — THE MANNINGTOS OIL FIELD.

or four general rules (which include practically all the limitations known to me.
up to tin' present time that should be placed on the statement that large gas wells
may be obtained on anticlinal folds), viz:

a) "The arch in the rocks must l>e one of considerable magnitude.
(b) "A coarse or porous sandstone of considerable thickness, or. if a tine-grained
rock, one that would have extensive fissures, and thus in either case rendered
capable of acting as a reservoir for the gas, must underlie the surface at a depth of
several hundred fret (500 to 2,500).

c " Probably very few or none of the grand arches along mountain ranges will
be found holding gas in large quantity, since in such cases the disturbance of the
stratification has been so profound that all the natural gas generated in the past
would long ago have escaped into the air through fissures that traverse all the l>eds.
[•It "Another limitation might possibly he added, which would confine the areas
where great gas flows may be obtained to those underlain by a considerable thick-
ness of bituminous shah'.

(e) " Very fair gas wells may also be obtained for a considerable distance down
the slopes from the crests of the anticlinals, provided the dip he sufficiently rapid,
and especially if it he irregular orinterrupted with slight crumples. And even in
regions where there are no well marked anticlinals, if the dip he somewhat rapid
and irregular, rather large gas wells may occasionally be found, if all other condi-
. tions are favorable.

'"The reason why natural gas should collect under the arches of the rocks is
sufficiently plain, from a consideration of its volatile nature. Then, to.,, the exten-
sive Assuring of the rock, which appears necessary to form a capacious reservoir
for a large ,^as well, would take place most readily along the anticlinals where the
tension in bending would he greatest.

" The geological horizon that furnishes the best gas reservoir in western Penn-
sylvania seems to he identical with the first Venango oil sand, and hence is one of
the Catskill conglomerates. This is the gas rock at Murraysville, Tarentum, Wash-
ington, Wellsburg, and many other points. Some large gas wells have been obtained
in tin- Sul .carboniferous sandstone (Pocono), however, and others down in the third
Venango oil sand (Chemung).

" In Ohio, gas flows of considerable size have been obtained deep down in the
Cincinnati limestone, while in West Virginia they have been found in the Potts-
ville conglomerate: hence natural gas, like oil. has a wide range through the geo-
logical column, though it is a significant fact that it is most abundant above the
black slates of the Devonian."

The conclusions announced in the foregoing article were criticised by Mr. Charles
A. Ashburner, geologist in charge of the geological survey of Pennsylvania, who
claimed, in effect, that the relation between gas wells and anticlinals was one of
coincidence merely, or of the same nature as Angell's " belt theory " of oil. and also
that large gas wells could he found in synclines.

To this criticism the writer published the following reply in Science, of July 17.
1 885 :

■" In reply to .Mr. Ashburner's criticism of the view- advanced in my article on
natural gas, I would say that the necessary brevity of the paper in question pre-
vented the mention of many facts that might have rendered the conclusion- clearer
and less open to challenge. < >ne of these is that my communication had especial
reference to the natural gas regions proper, L . .. where the gas is unconnected with

DEFENSE OK THE ANTICLINAL THEORY. 207

oilfields. Most geologists know that natural gas in large quantities exists with
and contiguous to every oil pool, apparently as a by-product in the generation of
the oil, and of course' the rucks arc filled with it wherever it can find a reservoir.
Togas wells from such sources Mr. Ashburner's criticism may sometimes he found
applicable; hut, even with these, by far the larger ones will be found on the arches
of the rocks.

"The cases that Mr. Ashburner mentions, where large gas wells have been found
at tic centers of synclines, do not necessarily contradict my conclusions ; for no one
knows better than he that a subordinate crumple or anticlinal roll often runsalong
the central line of a syncline.

"My excuse for writing the article on natural gas was that I might he of some
service in preventing the waste of capital that lias been going on within a radius
of fifty miles from Pittsburg by an indiscriminate search for natural gas; audit
is a sufficient answer to Mr. Ashburner's criticism to point him to the brilliant
lights along the crests of the Waynesburg, Pinhook, Washington, Hull creek, Bradys
bend, Hickory, Wellsburig, Raccoon, and other anticlinals, and also to the darkness
that envelops the intervening synclines, in which hundreds of thousands of dollars
have been invested without developing a single profitable gas well. The same
result has been proven in other portions of the country'. The Great Kanawha
valley above Charleston has been honeycombed with borings for salt, and the only
gas wells developed were found within a belt a few rods wide, which coincides with.
the crest of the Browntown anticlinal, where immense Hows were struck. In this
connection I should state that Colonel Allen, of Charleston, says he can trace the
Browntown anticlinal by the escaping gas across streams, and even mountains,
from the Kanawha river to the Big Sandy, where, on its crest, near YVarfield, two
of the largest gas wells ever known have recently been struck. At Burning springs,
on the Little Kanawha, the only large gas wells were found on the very crest of the
great uplift in that region. The gas belt of western Ohio, through Findlay and
other towns, follows closely the line of the Cincinnati arch, and the same story is
repeated in other localities too numerous to mention.

" Mr. Ashburner can, if he chooses, interpret these facts as mere coincidences,
and explain them to himself as having no more hearing on the question of finding
gas than " Angell's belt theory " of oil ; but the practical gas operator can no longer
be deluded by such logic into risking his money in water-holes (synclines) where
SO many thousands have been hopelessly squandered.

"With regard to the anticlinal theory not being'a practical basis for successful
operations,' 1 deem it a sufficienl reply to state that all the successful gas companies
of western Pennsylvania and West Virginia are getting their gas from the crests of
anticlinal axes, while those that have confined their operations to synclines have
met with uniform financial disaster.

"The statement was distinctly made in my original communication that gas
would not he found on all anticlinals, nor at all localities along one that actually
produces gas, since other factors have to be considered, as there stated; but, with
the facts before US, it would certainly prove a great saving of capital in the search
for Lias if operations were confined to the crests of the anticlinals, and I fail to
perceive how Mr. Ashburner's fear- for i he ■ misleading' character of my article can
he realized."

Mr. Ashburner replied to this in Selene of September !, 1885, and lias written
further on the subject in a paper read before the American Institute of Mining

208 I. C. WHITE — THE MANNINGTON OIL FIELD.

Engineers, Halifax meeting, 1885, and also in 7V/,' Petroleum Age for January, 1886.
As a general reply to these stricture.-: ami also to illustrate the theory more fully,
the writer prepareda paper for The Petroleum Age which was published in the March
number of that journal, along with a map of western Pennsylvania, on which were
located the principal anticlinal lines, and also the large gas wells. Since the article
in question contains several points of interest not hitherto given to the public, the
principal portion of it is here republished, without the map, which can lie procured
from The Petroleum Age by any reader who wishes it for reference :

" Where the anticlinal lines are drawn full on that map they represent actual
observations of myself or others, but the dotted lines are projections of arches ob-
served only at a few points ; for instance, Mr. Ashburner states that the Sheffield
gas wells are on the crest of an anticline, and when the Martinsburg axis of Mr-
Chance is projected approximately parallel to the others it passes through the
Sheffield region ; hence the two are assumed to be identical, and the same principle
has been followed in making the other projections.

"There are probably other flexures in the rocks which traverse the district in
question that, in the rapid survey made of some of the counties, were not detected
by the assistant geologists of the Pennsylvania survey. The writer pleads guilty
to some mistakes of this nature, as well as of getting one anticlinal confused with
another, in the case of the Fredericktown uplift. Tins mistake, which was cor-
rected by Mr. II. Martyn Chance, in report V, may possibly have been duplicated
by others of the assistants before they became expert at detecting minute changes
in dip or stratification.

"An inspection of the accompanying map will reveal the fact that the main
northeast and southwest anticlinals are cut by another set at nearly right angles,
which have been termed cross-cut anticlinals. To Mr. Ashburner belongs the credit
of first calling the attention of geologists to this feature in the rock structure of
Pennsylvania, and the great Kinzua-Emporium cross-cut wave which he first traced
through Cameron, Elk and McKean counties is shown on the present map.

"The surveys of the western counties of Pennsylvania were practically finished
before the publication of Mr. Ashburner's observations in the northern portion of
the state, and hence although similar phenomena were observed they were not
described in similar terms or referred to similar causes. Thus. Stevenson (as well
as Rogers long ago) recognized a great bulge in the Chestnut ridge uplift, near
I niontown, by which the Hamilton rocks are elevated to the summit of the moun-
tain, but the arch dying down both north and south, the Catskill rocks fail to reach
the surface where the axis crosses the gorge of Cheat river in the one direction, and
the Chemung- beds are completely buried at the ( lonemaugh gap in the other.

" During the last two years the writer has given considerable thought to these
cross-cut axes, and the results show that a cross-cut anticlinal (presumably identical
with the one crossing Chestnut ridge near Uniontown) goes through the famous
Cannonsburg and Hickory gas regions in Washington county, while another par-
allel to it, and a few miles west, goes through the village of Pinhook,or Lone Pine^
and also cuts the Mc< hiigan gas field.

"Another of marked extent has recently been traced by the writer through the
Murraysville and Grapeville region of Westmoreland county, the greatest gas field
in the world, so far as present developments show. < rroups of wells also appear to
cluster along the grand arch that Mr. Ashburner has traced through northern
Pennsylvania.

"Having observed the importance of these cross-cut arches in the location of gas

CORROBORATION OF THE ANTICLINAL THEORY. 209

territory, I wrote Mr. Ashburner, suggesting that there might be some disturbance
of the rocks in the region of Kane, where he claimed large gas wells were found in
an undisturbed syncline.

"The recent discovery of oil in the Kane region has led to the drilling of many
wells, and in the Oil City Derrick of a recent date the statement is made on the
authority of Mr. McKinney, of the Union oil company, that a rapid northward dip
had been found, i. e., a subordinate cross-cut anticline parallel to the main one
north of Kane passes through the Roy and Archer gas region. Whether this shall
turn out true or otherwise, there is certainly no inherent improbability against
rinding such subordinate waves.

" Very unexpected and surprising was the testimony on this head which came
to me recently from Mr. L. R. Curtiss, of Mendota, Illinois, who, unknown to my-
self, made a careful study of the geological conditions under which natural gas
occurs in that state, and reached the same conclusions quite independently of my
own views, as will he seen from the following paragraphs, quoted by permission
from his letter to me on the subject :

"'The principal anticlinal axis of Illinois puts out in Ogle county, in the
northern part of the state, and extends in a direction S. 20° E. through La Salle
and Champaign, and thence to Coles and Clark counties, in the southeastern part
of the state. Along this axis natural gas can be traced in springs and well borings
for a distance of 160 miles. // is, however, more prevalent mi the crovms of the cross-
axes. This is notably the case at Mendota, where the cross-axis intersects the
main anticline at an angle of 85° (running S. 65° W.), and on the summit of this
fold the gas belt extends southwestward into Bureau county for over twenty-five
miles. The other cross-axes located further to the south intersect two or three
low anticlinals toward the Mississippi, and trend in the direction of the gas
fields in McLean, De Witt, Macon, and Montgomery counties.'

" This same story is repeated in Ohio, according to the testimony of the eminent
state geologist, Professor Orton (set' his letter in Ohio State Journal of recent date).

"Now what is the effect of these cross-cut axes on geological structure? Evi-
dently one effect would be to cause the arches and corresponding troughs them-
selves to rise or sink, as we approach or recede from the cross-cut as the case may
be; for example, the general rule is that the rocks of western Pennsylvania dip
down to the southwest along the line of the anticlinals, as well as away from
them (N. W. and S. K.i.hut in the region of Cannonsburg this rule is reversed and
the rocks rise rapidly (seventy-five feet per mile) to the southwest along Loth
anticlinals and synclinals until the crest of the Hickory-Houstonville cross-cut
arch is passed, when a rapid dtp begins in the same direction (southwestward),
thus forming at the points of intersection a kind of " hog-back " structure fas Mr.
Earseman terms it) from which the rocks dip away in every direction.

" Hence these cross-cut arches result in carrying the anticlinal structure and a
line of disturbance in the rocks directly across the trend of a syncline, and a fail-
ure to grasp this fad is the principal reason why Mr. Ashhurner insists upon his
readers believing that a greal gas well may be obtained in a syncline; for it
is quite certain thai no large gas well has ever yet been found in the trend of a

syncline, except where the trough itself has Keen elevated by a Ion- rise from the

Bouthwest, which is. of course, broughl aboul by the cross-cut folds.

"These are the geological surroundings of all those wells which Mr. Ashburner
cites from northern Pennsylvania and southern New York as, occurring in syn-
clines. It is not necessary to show a reversed or northeast dip in order to

210 I. C WHITE — THE MANNINGTON oil- FIELD*

demonstrate the existence of one of those cross-cut waves, since their crests are
i like some of the main northeast and southwest anticlinals) often marked by a
simple flattening of the rate of dip along the latter. Professor < >rton would call
such a structure (where there is no reversal of dip, but only a change in rate)
a suppressed anticlinal, a very good name, for such it really is.

"It follow-, of eourse, that as a synclinal structure may be converted into
an anticlinal one by the presence of the cross-cut wave, so the reverse may and
frequently does happen, of which we have a. notable instance in the region
immediately adjoining Pittsburg. Here the anticlinals all sink down toward the
southwest until we reach tin- bottom of a cross-cut trough, where they begin
to rise again toward Cannonsburg, the result of which is to flood all the porous
rocks under Pittsburg with salt water. The numerous wells drilled at Pittsburg
show a good reservoir (Mr. Ashburner's prime factor for gas wells) ; hut geological
structure dominates here as everywhere else, and Alls the reservoir with water, so
that the little uas obtainable is practically useless, though when structure has
elevated this reservoir out of the water at Tarentum on the north and Cannons-
burg on the south, gas is obtained in abundance.

"Another cross-cut anticlinal passes along the Conemaugh rive)', intersecting
Leechburg and Butler, its path being marked by a line of gas wells across syn-
clinals as well as anticlinals.

"Having now glanced at some of the general structural features under which
large gas wells are found, we shall consider a few of the individual arches and
troughs in order to illustrate some of the general principles to which reference has
been made.

"Laurel Will "//</ Chestnut Ridgt Anticlinals. — The arches made by these great
axe- would, in my opinion, come under the ban of exception (c), and hence the
rocks would probably be fissured too much to retain large quantities of uas. This
i- only an inference from theory, however, since so far as I am aware only one or
two wells have been bored near the crown of either arch. One of these was
bored for oil in Monongalia county, West Virginia, when/ the Chestnut ridge axis
crosses Decker's creek, six miles southeast of Morgantown. This well began at the
base of the no. XI limestone and descended about 400 feet, and hence did not pene-
trate the great Murraysville gas horizon | first Venango oil sand). Whether or not
these large arches may furnish gas when they have flattened out to much lower
waves in northern Indiana and Cambria counties is a question that only the drill
can settle, though the fact that some gas was obtained at Cherry Tree, near the
Nolo anticlinal diet ween Laurel hill and Chestnut ridge), would seem to renderthe
hope not entirely groundless. In fact it is within the range of possibility (though
not probable) that if a hole were sunk to a great depth on these arches, where
they exhibit even a large development, uas might he found. The drill has this
question to settle yet, since the two deep wells drilled in the synclines at .Johnstown
and Wellersburg could not he expected to find uas. Those drilled in the Ligonier
valley were also in a syncline, and hence obtained only small quantities of gas.

'' Coming still further westward we find that several wells have been bored along
the western slope of Chestnut Ridge, about half way down the dip from the crown
ofthearch. One of these on Deckers creek and two on ( 'heat river. We.-t Virginia,
found a considerable quantity of gas in no. XII (the first urea t gas horizon), but the
rock, as might have been expected, was filled also with water, which rendered the
uas useless. The wells bored under nearly the same conditions as to locations in
Westmoreland countv found very little gas.

EARLY TESTS OF THE ANTICLINAL THEORY. 211

"The next arch westward from Chestnut ridge is the Indiana axis of Piatt. This
is a very sharp and well defined wave in Westmoreland county, the vertical distance
from the crest to the bottom of the troughs on either side being in some places not
less than 800 feet or even more ; hence, unless its proximity to the great arch of
Chestnut ridge should affect it, we would on the 'anticlinal theory' naturally
expect it to furnish good gas wells, provided the proper kind of reservoir exists
under the surface. Messrs. Guffey and Mellon have recently finished a well on this
arch near Latrobe, which yields from five to six hundred thousand feet of gas daily.
Some drilling was once done in the vicinity of Blairsville, where the arch crosses
the Conemaugh river, but no large flow of gas was obtained, probably because the
well was situated too far from the crest of the arch.

"Going still further northeastward we find the well which supplies the town of
Punxsutawney with gas is situated close to this fold.

" The next arch is the great Saltsburg axis of Stevenson, the descent on each
side of which is quite as great as that of the Indiana arch. This is far enough away
from the ( Ihestnut ridge disturbance to remain unaffected by the latter, and hence
ought to furnish a fair test of the 'anticlinal theory.' The writer recently located
a well on this arch for J. M. Guffey & Co., just north from the town of Grapeville,
and when the Murraysville sand was reached a few weeks ago an immense flow of
dry gas was struck.*

"Some gentlemen from Greensburg, however, who, like Mr. Ashburner, seemed
to think gas could be obtained in a syncline, drilled a well one mile east from the
crest of the arch, at a locality where the dip had carried the rocks down "_'">() feet
below the crest of the Saltsburg wave. The result was that although a splendid
reservoir of great thickness was found, it contained an immense supply of water,
and consequently what little gas was obtained was worthless. These wells, theone
furnishing a large gqs How and the other a large water flow, are only two and one-
half miles apart, the former on the crown of the arch, the latter nearly a mile east
from the same. No fairer test than this could be asked for the merits of the "anti-
clinal t henry."

" The next arch westward is the Waynesburg axis, and the only gas wells obtained
along I he Monongahela river, among the many that have been bored, are found on
its crest at Bellevernon, though the fold being low and flat, no large wells have been
struck.

"The great Murraysville arch was regarded by Professor Stevenson as identical
with the Waynesburg fold, the latter having been shifted eastward; but. however,
this may be, there is no doubt about the one dying away to the north and the
other to the south, and hence I have termed the western fold simply the Murrays-
ville axis. This, like many other well known arches in Pennsylvania, is a double
fold, with the crests al lout one-half mile apart, though the depression between them
is very slight. As every "tie knows, the forty or more great gassers in that region
are clustered along the Murraysville anticlinal, water being obtained in the syn-
clinal at Irwin on the east and at Walls on the west. ' But,' says the opponent of
the ' anticlinal theory,' ' you get water with the gas even along the Murraysville

*" Since this was written two other wells have i n drilled to the Murraysville sand, on the crown

of the Saltsburg arch, near Grapeville, and competent judges', who have seen all the great gas wells

hi the i iii r> . pronounce thei !i the largest that have ever yel i d struck ; 30 that mj >

diction of tin igo, that the ftrapi 1 ill ■ region would furnish 1 irger wells than the Mm 1

■ iil'\ 1 1:1- been literati] fulfilled, This conclusion was based on geological structun alone, - n the

'.. ipeville, "i- Saltsburg arch, is n mm li grander than the Murraysville fold. Van Mi Vsh-

burner explain this awaj as i ease of coincidence of the \ngell " bell theorj 'Kind'/
SXV1II— B 801 Vti., V.. 1 1, 1891

212 I. C. WHITE — THE MANNINGTON OIL FIELD. t

arch when you come south of the Pennsylvania railroad; hence of what account is
the theory, anyhow ? ' 'My critical friend,' we answer, 'you have not observed
wisely, else yon would have seen that the Murraysville arch dies down and flattens
out very rapidly into the greal cross-cut syncline trough which embraces the city
of Pittsburg, and a broad bell on either side, and tin- •anticlinal theory' of gas
teaches that it is quite a- unwise to expect large gas wells on an arch so situated
structurally as in a genuine syncline; for whenever the dip along the axial line
begins to equal or surpa>^ the total height of the wave, water may he confidently
expected.' Hence, although some very large flows of gas have been struck near
where the Murraysville arch crosses the Youghiogheny river, yet the quantity of
water in the rock was so great that the gas was soon drowned out. The same
principle accounts for the water in the Venice well of Washington county, which
is located near the structural line of the Bradys bend axis, and so of others that
have been pointed to as contradicting the •anticlinal theory.' And thus we might
•jo over the entire list of anticlinals ; hut as the story would be practically the same
everywhere, it is useless to tire the reader's patience with details. It has been
shown that the great gas wells cluster along the anticlinals. and where any marked
exception to this rule occurs we tind a cross-cut arch is the disturbing cause, and
hence the seeming conflict is the strongest confirmation of the real essence of the
'anticlinal theory,' which, condensed and simplified into the fewest words, means
that structun is the main factor in a search for great gas wells; that disturbance in
the rocks by which they have been elevated above the same beds in contiguous
regions, either on the crest of an anticlinal arch or along the axial lines of the syn-
clines themselves where cut by the cross-arches) is an essential element in finding
large ami lasting wells, free from water, and therefore entitled to be called ' great.'

•• It is true that a considerable quantity of gas may he so shut in by close rock
(through which it cannot pass as to be imprisoned even in a syncline, and when
first struck may deliver a large quantity of gas, and the same may he true where
the rocks are nearly horizontal, especially in regions contiguous to oil territory ; hut
such wells soon blow themselves out and cease to deliver gas, like the famous
■ .Mullen Snorter' and ' Kane Geyser,' which figure so largely in Mr. Ashburner's
criticism of the 'anticlinal theory.'

"Reference has also been made to the gas well- at Erie and Fredonia as evidence
against the 'anticlinal theory,' since it is claimed there are no anticlinal wave.- near
these localities. To any one who deems these wells evidences against what 1
have claimed for the •anticlinal theory,' 1 must request him to read more carefully ■
the quotations from my original paper found in this article, where he will not find
the statement that all gas wells occur on anticlinals, hut instead, all great gas wells
are found close to anticlinal arches. Now what is a ' great well'.'* It is probable
that no L:as well yet struck ever delivered more than thirty to thirty-five million
cubic feet of gas daily. Some have been measured in the Murraysville field that,
if we can believe the figures, have yielded thirty-three million feet daily. This is
one extreme; hut certainly by no stretch of language could the term 'great' be
applied to wells like those of Erie, Fredonia and elsewhere along lake Erie which,
according to Professor Orton's measurements, yield only from twenty to sixty
thousand feet daily.

" Moreover, so far as Erie is concerned, a recent and careful study of the stratifi-
cation there has revealed to the writer the presence of low waves in the same.
approximately parallel to the lake, which were undetected in the necessarily hasty
examination made several years ago for the Pennsylvania geological survey.

LAW'S OF GAS ACCUMULATION. 213

"As every one knows, it is scarcely possible to penetrate the earth to a consider-
able depth anywhere within the Paleozoic area (except the rocks are highly con-
torted) without getting some natural gas, but the largt supplies are confined to
restricted areas, and it was to prevent the waste of capital in an indiscriminate
search for these great stores of valuable fuel that prompted my original article on
the subject. The drill will, of course, finally settle the question as to whether or
not my conclusions were valid. Something, however, hasalready been accomplished
in this line.

"A map of Ohio would reveal the same condition of affairs, for there areonly two
or three prominent anticlinals in the state, and after the expenditure of a vast
amount of money in drilling, the only large gas wells have been found along these
lines of disturbance. Kentucky, Illinois and West Virginia tell the same story ; so
that there would seem to be no good reason for any one longer to doubt that structure
is the great factor in securing Large and lasting pis wells.

'" If, however, some skeptical capitalist shall ever find large gas wells, free from
water, in a genuine syncline, like that at Greensburg, Pennsylvania, or at the
bottom of the trpugh near Irwin, then I shall frankly confess that my judgment
has been imposed upon, and that geological structure can give no clue to this hidden
t reasure.

"The reasons why the gas should he stored most abundantly along the arches
are so patent that it is unnecessary to state them ; the insoluble problem would be
how to imprison large quantities of gas in a syncline. except what little might exist
in water under high pressure.

"' If our main proposition be true, viz, that the principal supplies of natural gas
have been stored along the arches of the rocks, then the question of local',,),! must
have a very important bearing upon the life of any particular gas field ; for what-
ever may have been the source or origin of the gas, whether as a by-product in the
genesis of oil fas much of it certainly isi, or from the action of heated saline water
mi carbonaceous material, thus originating the Murraysville or odorless gas with-
out any oil, as some claim, or in what way soever it is produced, the wells along
the arches would have a much longer lease of life.

"Mr. ('aril has recently sounded a note of warning through the columns of Th
Petroleum Age, to which those who think the supply inexhaustible would do well
to take heed ; for certain it is that many wells once large have long since ceased to
flow. It is true that many of these have hern choked up with salt because the
water was not cased off, and the casing having been taken out. a column of water
many hundred feet high has imprisoned others, but there is reason for believing
that still others have failed because the source of supply was exhausted. On the
'anticlinal theory.' it would be expected thai all wells not situated near prominent
arches, nor at the upturned ends of vanishing synclines, could not have a long life,
since the contents of the reservoir upon which they can draw must necessarily be
of limited extent. Bui not so with t hose situated along the prominent a indies, like
that at Cannonsburg, Murraysville and Grapeville; for here the quantity in any
one sand will be vastly greater than where the rocks are undisturbed, and the dis-
turbance itself will have fractured the rocks and thus given access to many other
reservoirs below the one from which the well draws immediately.

"Thefirsl Murraysville well has been delivering from fifteen to twenty million
feet of gas daily for nearly ten years, and set. with many other well- in close prox-
imity, its volume has not yel been appreciable diminished. Hence there is good
reason for believing thai the gas wells situated on the pr inenl arches uiaj have

211 I. C. WHITE — THE MANNINGTON oil. FIELD.

a much longer life than others not so fortunately placed, and that the immense
amount of capital invested in pipe lines to them will receive an adequate return
he fore the gas shall have been exhausted. Nothing hut time can determine the
life of gas territory situated upon a well developed arch, like the Murraysville or
Saltsburg anticlines.

"In Washington county, Pennsylvania, there are three principal geological hori-
zons at which large supplies of gas are found, and, taking the Pittsburg coal as a
datum line, these horizons come in as follows, neglecting fractions:

Fret.

First horizon, below Pittsburg coal 900

Second " " " " 1,800

Third " " " " 2,000

"The first horizon furnishes a gas very much like the .Murraysville gas, and the
pressure seldom rises above 300 pounds to the square inch. It is contained in the
no. XII conglomerate, since the rock lies about 200 feet above the Subcarboniferous
limestone.

"The second horizon is identical with the first Venango oil sand, and seems to lie
the gas horizon par excellence of southwestern Pennsylvania, since it is also the great
producing rock in Beaver, Alleghany, Butler and Westmoreland counties. It is
nearly always overlain by a dark, close slate, which has evidently been a factor in
enabling the rock to retain the gas. The product of this rock is strongly scented
with petroleum in Washington county, but at .Murraysville and Grapevine, in
Westmoreland, it is nearly odorless, though it is oil-scented again near Latrobe.

" This same rock is the gas reservoir at AVellsburg, West Virginia, and has there
been identified by Professor Orton as the Macksburg oil sand, which he in turn
identities with the Berea grit.

" The third great gas horizon of Washington county is in the 'stray,' or upper-
most member of the third Venango oil sand. The famous Mel ruigan well is in this
sand, as also the Donaldson, Willison, McClean, and others in Washington county.

"The total pressure to which the gas from this rock will rise, when shut in, has
never been determined, so far as I am aware, hut it would probably exceed that
from the first Venango, or Murraysville sand, which seldom rises above 050 pounds
to the square inch.

"The explanation of uas pressure in any particular rock seems as yet unite
obscure, but there is evidently an increase of pressure with increase of depth,
though the law of increase (if there be any law) is not uniform. For instance, the
wells at Erie which go down 600 to 700 feet, show a maximum of only 40 to 50
pounds. Mr. Westinghouse, of the Philadelphia company, Pittsburg, suggests that
the gas pressure in any case may be due to the water, or hydrostatic pressure on
the rock, and this is possibly true, since it would account for the greater j^ressure
as the sand gets deeper below the surface."

Since the above statements with reference to the Washington county gas horizons
were written the drill has developed two others, viz, one in the "Big sand," or
Manifold farm oil rock, which begins directly under the Mountain or no. XI lime-
stone, and is 250 feet thick. This rock is the upper member of the Pocono sand-
stone, and is called in Ohio the "salt sand." The horizon in it which furnishes gas
is about 1,150 feet below the Pittsburg coal.

The other gas horizon is the so-called "50-foot rock," which has proved so prolific
in oil at the Smith no. 1. The top of this sand conies about 1,850 feet below the
Pittsburg coal, and it is very probably identical with the second Venango oil sand.

THE CRITICISMS OF THE "ANTICLINAL THEORY" OF NATURAL CAS.-

READ AT THE BUFFALO MEETING OF THE AMERICAN ASSOCIATION FOR THE
ADVANCEMENT OF SCIENCE, AUGUST, L886, BY I. C. WHITE.

Through inexcusable carelessness (for I cannot be so uncharitable as to charge
intentional misrepresentation), the critics of the "anticlinal theory" of natural gas
liave invariably misapprehended its claims, and criticised something other than
this theory as held and promulgated by the writer.

My critics have almost invariably written about the theory as though it had been
claimed that large gas wells could be found everywhere on every anticlinal roll,
and in no other situation whatever. Messrs. Ashburner, Chance and Carll, of the
Pennsylvania survey, have all set up for themselves this " man of straw," and of
course easily demolished him, since no one with whom I have any acquaintance
has ever held or published any such theory of natural gas occurrence as they com-
bat. The eminent director of the Pennsylvania geological survey, in his presi-
dential address at Ann Arbor last year, found occasion to refer to the " exploded
anticlinal theory of natural gas " as a splendid piece of "dead work," accomplished
presumably by the critics already mentioned. It is true that this " dead work"
has effectually buried the anticlinal theory as put forth by these critics, for neither
the writer nor any one else ever held such a theory ; but substantially all that I
have ever claimed for it has now been so thoroughly established by the " live
work" of the drill, that no geologist, well informed on the subject, will be so i*ash
as to deny the fact.

The gentlemen who have so freely criticised the "anticlinal theory "seem to
have stopped reading my first paper on the subject, in Science of June 2P>, 1885,
when they came to the limitations placed on the theory. On no other hypothesis
can I understand the grounds of their opposition. Those who have interest enough
in the matter to desire to read my papers on the subject will find all of them in the
"Natural Gas supplement " of the American Manufacturer; and after having done
so, they will find that the essence of it all is, that the .meat supplies of natural gas
have accumulated in the rock reservoirs, in regions of disturbance by which the
reservoirs in question have been elevated above contiguous areas of the same beds,
and in the lower levels of which oil and water may be expected ; or, in other words,
uas lias accumulated where anticlinals or monoclinals of considerable (but not too
great) extent have raised the rocks into arches and other forms of elevation ; and
hence, as Professor Orton says, structuri is the main element in the occurrence of
Lias and oil in large quantity.

The theory teaches that it is useless to bore for large gas supplies in a region
where there are no considerable or irregular dips, and hence its negative value is
of great importance, since in my own experience but a single failure has been
made in condemning such regions ; and if any further proof was needed, the larger
portion of tiie state of ( )hio bears unmistakable testimony to the negative value of
the "anticlinal theory," %

But probably the strongesi testimony in favor of this theory is the almost uni-
versal approval of t lie practical operators. Many of these, I find, have been guiding
their own operations on I he same principle for many years, and I very much doubt
whether a single operator in Pennsylvania could lie induced to drill for gas in a
well marked syncline.

► Read by title only at the meeting of the \. \. L 8. in Buffalo, Uigust, 1886; subsequently pub-
lished in The Petrol > foi No ember, 1886 (vol. v, pp. 1464, 1465), from which it is reprinted.

21r> I. C WHITE — THE MANNINGTON OIL FIELD.

The -rent gas fields of Washington and Grapeville, which the writer located on
this theory,are sufficient evidence to most people that its claims are not entirely de-
lusive, or the result of coincidence, as my friend Ashburner would have us believe.

A map which the writer prepared to accompany an article on natural gas in The
Petroleum Age has also been a source of trouble to some of my former associate's on
the Pennsylvania geological survey. One in particular says some very unkind
things about it: First, that the scale is too small ; second, that the anticlinals are
incorrectly placed; and, thirdly, that Mr. Ashburner's "great" Kinzua-Emporium
cross-cut anticlinal is a myth, as likewise all the others, both "great " and small,
which appear on the map in question.

As to the first count in this indictment, I claim exemption from blame, for the
original map prepared for this purpose was on a scale of six miles to the inch,
instead often, as published, and the editors of the Age will bear witness that I
desired the larger scale, which they declined to publish on account of expense.

As to the second Count, I would say that the mechanical execution of the map
was committed to Messrs. Johnson and Grafton, two young engineers and experi-
enced draftsmen, who put the anticlinals on the ma]) from data furnished by
the publications of the Pennsylvania geological survey, except, as stated in my
accompanying paper, I took the liberty of correcting some of my own work from
later and more detailed observations in the southwestern part of the state; and
hence, if any serious error exists in the placing of the anticlinals, it is not the fault
of the writer.

With regard to the last count, the writer pleads that he did not invent the term
•' cross-cut anticlinal." since, in the paper to which reference has been made, he
gives due credit to its author and discoverer, Mr. Ashburner. If the black line
which has been stereotyped so Long on the McKean, Elk and Cameron county maps
of the Pennsylvania geological survey, under the name of " Kinzua-Emporium
cross-cut anticlinal," is really a myth, as Mr. Ashburner himself seems now not
unwilling to admit, then the writer shall certainly raise no objections to having the
term erased from geological nomenclature, as well as from the maps in question;
but the structure that the writer described under this term will not he changed by
a change of name.

As is well known, the main anticlinals of western Pennsylvania extend in a
northeast-and-southwest direction, and, as a general rule, the rocks dip down to the
southwest along the lines of the anticlinals as well as those of the synclinals; but
in some regions, notably at Washington and < hrapeville, there is such a swelling up
of the anticlinals that the rocks rise rapidly to the southwest instead of dip, and as
some of these bulges on the different anticlinals are in a line with each other, I
thought it not improbable that they might be connected in origin at least, and
hence, having no other name at hand, adopted the one already coined by Mi-. Ash-
burner for what I supposed represented a similar structure.

But whatever we may call the structure in question, whether a swell, bulge, or
"hog-back," as one gentleman terms it, the localities where it occurs are those par
excellence where we may expect large deposits of natural gas; and when large wells
have been obtained in the trend of a syncline the structure is found to he compli-
cated by the presence of such a bulge, or else a long and rapid rise from the southwest.

The writer knows that the anticlinal theory, taken in connection with thelimita-
tions, which are a necessary part of it, is a valuable guide to the geologist in search
of natural gas deposits, because he speaks from an experience of more than three
years, in which the theory has been put to many practical tests.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 217-218 April 15, 1892

FOSSIL PLANTS FROM THE WICHITA OR PERMIAN BEDS

OF TEXAS.

BY I. <'. WHITE.

In the spring- of the present year. Mr. E. T. Dumble, state geologist of
Texas, sent me for examination a small collection of fossil plants from
the Wichita beds of that state.

These plants were discovered and collected by Mr. W. F. Cummins,
assistant on the Texas survey. They occur in the Wichita beds along
with invertebrate remains which Dr. C. A. White lias assigned to a Per-
main age. and vertebrate remains which Professor Cope asserts are of
the same age. 1 was therefore quite anxious to know what answer the
plants might give to the question of supposed geological equivalency
between the Wichita series of deposits and those at the summit of the
Carboniferous column in southwestern Pennsylvania and West Virginia
and in southern Ohio, where the invertebrate and reptilian remains are
absent, or at least not yet discovered, though plan! remains are abundant.

These West Virginia beds above the horizon of the Waynesburg coal
had long ago (1878) been referred to the Permian by Professor W'm. M.
Fontaine and myself,* upon the evidence of the fossil plants found
therein : but as the correctness of this reference had been questioned, or
at least not generally recognized by American geologists, the opportunity
to compare this flora with that of a locality containing a Permian fauna,
through the kindness of Mr. Dumble, was heartily welcomed.

After such cursory examination as I could give the plants when firs!
received, I saw at a glance thai they were either identical with, or very
near relatives of, our West Virginia plants from the beds above the
Waynesburg coal, and so wrote Mr. Dumble at the time. Bui to be
certain of the matter, I sent the plants to Professor Win. M. Fontaine,
the distinguished paleobotanisl at the university of Virginia, who at my
requesl examined the collection and sent me the following li-t of iden-
tifiable species ;

* I'l'. Ponnsyh mi i Si < I Rpologienl Survej .

(217)

218 I. C. WHITE FOSSIL PLANTS FROM TEXAS.

Sphenophyllum latifolium, F. & \V. Pecopteris lanceolata, F. & W.
" filiculme, Lx. " platynervis, F. & W.

Annularia, near radiata, Brt. " latifolia, F. eV' W.

Wnlcliiii. sp. ? •• imbricata, F. & W.

Odontopteris nervosa, F. &. \V. ;' tenuinervis, F. & W.

Callipteris conferta, Brt. " scpimperiana, F. & W.

Callipteridium oblongifolium, F. & W. rotund/folia, F. & W.

dawsonianum, F. & \V. candolleana, F. & \Y.

grandifolium, F. & \\T. Goniopteris oblonga. F. £ W.

iMwtam, F. & W.

A few other new or indeterminable forms were present, one badly
preserved specimen resembling Lepidodendron.

Professor Fontaine appends the following remarks concerning the geo-
logical horizon of the plants in question :

" I am decidedly of the opinion that this Texas flora is essentially the
same with the flora described by us in report PP of the second geo-
logical survey of Pennsylvania. The Walchia is the only important
determinable plant not present in the flora of West Virginia and Penn-
sylvania."

This conclusion of Professor Fontaine exactly confirms my own as
given in Bulletin 65, United States Geological Survey, page 42, before I
had seen the plants in question.

It follows from the evidence of this list of plants, as well as from
general stratigraphic facts, that the age of these uppermost rocks of the
( 'arboniferous system in West Virginia, southwestern Pennsylvania and
southern Ohio, or the Dunkard Creek series,* as I have termed these
deposits above the horizon of the Waynesburg coal, is the same as that
of the Wichita beds of Texas ; and if the latter be referable to the Per-
mian on the basis of their reptilian and invertebrate remains, then geol-
ogists can no longer refuse to recognize the Permian age of the Dunkard
Creek series, since, as shown by the list given above, every determinable
plant sent me from the Wichita Series except one {Walchia) has been
found in the Dunkard Creek beds.

The plants of this list were collected by Mr. Cummins from the upper
portion of the Wichita at the head of Godwins creek, Baylor county.
Texas, and from three miles west of Antelope, Texas.

* Bulletin 65, U. S. Geol. Survey, 1891, p. 20.

bull olol soc am

MAN XING TON

FAI RV1EW

MT MORRIS

Pfrmo
Carboniferous

Upper Coal
Measures

BarrenMeasujes <

lower Coal
Measures

PoitsvUle
Conglomerate

Ma uch Chunk
Shale

Mt. Lime stone

Pocono Sand Stone

or 4

Bigln|un Oil Sand

£££?

e^*^*

Wi 881

:(■;. ', ; ; 4 '. ; ■

Sea Level

VOL III 189. PL 6.

4- ! TAYLOR

it—

£ a

(6 Sea i."vi-l

of tV

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 219-230

NOTES ON THE GEOLOGY OF THE VALLEY OF THE MIDDLE

RIO GRANDE

E. T. DUMBLE

ROCHESTEB

PUBLISHED BY Tl II-: SOCIETY
Ai'Kir., 1892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 219-230 April 22, 1892

NOTES ON THE GEOLOGY OF THE VALLEY OF THE MIDDLE

RIO GRANDE.

BY E. T. DUMBLE.

(Presented before the Society December 31, 1892.)

CONTENTS.

Page.

Introduction 219

Topography 220

Geologic Structure 220

Lower Cretaceous 220

Upper Cretaceous 221

The Val Verde Flags 221

The Pinto Limestone 222

The Eagle Pass Division 224

Upson Clays 224

San Miguel Beds 224

The Coal Series 225

Escondido Beds 227

The upper Cretaceous Section 229

Reynosa Beds 229

Correlation of Rio Grande and Colorado River Sections 230

[introduction.

Tin; following statements arc based partly on observations made dur-
ing a trip from Eagle Pass to Edinburg by row-boat in the months of
May and June, lss*.), and partly on work in the region between Del Rio
and Eagle Pass during- the summer of 1891.*

A portion of the area having been described by Dr. R. A. V. Penrose,
Jr., in the first annual report of the Geological Survey of Texas, in the
present article I propose to confine myself to that pari of the river
between San Felipe creek, near Del Rio, and Webb bluff, three miles
below the southern Line of Maverick county. A Line joining the two

* The greater portion of tl iction above Eagle Pas was made in company with Mr. J. Owen

who rendered valuable assistance bj In accurate knowledge of the region on both ddesol the Ititi
1 (rande,

XXIX Urn Geol. Soc. \m., \ 01 . 3, 1891. \-\''

220 E. T. DUMBLE — GEOLOGY OF THE RIO GRANDE.

points has a direction S. 27° E., and a length of 81.7 miles. The distance
hy the river is probably half as much more, or one hundred and twenty
miles. The general direction of the dip is about 8. 45° E., which in this
region of very slightly inclined strata makes the section practically
follow the clip .

Topography.

For the distance given, the Rio Grande flows in a valley eroded in
Quaternary (or later Tertiary) and upper Cretaceous sediments, and its
hanks vary in character with the different materials of which they are
composed. When the strata are of sufficient hardness, bluffs of from 50
to 100 feet in height are found stretching along on one side or the other
of the river, while opposite there is generally only a gentle slope from
the water. In places the line of hills drops back some three or four
miles from the river, leaving broad fertile valleys. The general nature
of the topography, while resembling that of the same formations in cen-
tral Texas, is characterized by somewhat more angular and stronger lines,
due, no doubt, to the difference in climatic conditions. The tributaries
which empty into the Rio Grande on the Texas side are mostly small
and carry comparatively little water. The principal creeks are San
Felipe, Sacatosa, Sycamore or San Pedro, Pedro Pinto, Cow, Texaquito,
Las Moras, Elm, Rosita, Willow and Cuero. On the Mexican side, how-
ever, there are bold streams which add considerably to the volume of
water in the river. Among them are the San Diego, Escondido and San
Domingo rivers.

The elevation of Del Rio, according to the Southern Pacific railroad
engineers, is 073 feet; that of Eagle Pass, by the same authority, is 762
feet. According to a line of levels run for an irrigating canal, the bed of
the river is 120 feet lower at Eagle Pass than at the falls some forty miles
above, giving about three feet fall per mile in direct line, or about two
feet per mile of river. All of the falls and rapids, which are numerous,
are caused by the edges of the harder strata as they are carried under by
the dip.

Geologic Structure.

lower cretaceous.

The town of Del Rio is situated on the Arietina clays, which have here
a great development. Just southeast of the town there is a conical hill
or "mountain " 100 feet, or possibly more, in height, composed of clays
and shales and containing great numbers of shells of Exogyra arietina.
Roemer, Nodosaria texana, Conrad, and various other fossils. The hill

OLDER CRETACEOUS DEPOSITS. 221

is capped by gravel. Toward the south and east rises a scarp composed
of the same Arietina clays and Nodosaria shales.

The deposits of ochre which have been reported from this district
occur in these Arietina clays in the form of segregations of ferruginous
matter in bodies of considerable size but somewhat variable quality.

The clays and shales of the scarp are capped by a fine grained sub-
crystalline limestone of creamy white color, semi-conchoidal fracture,
and containing many small reddish spots. This limestone is litho-
logically and stratigraphically equivalent to the Vola limestone of the
Colorado section, and although no fossils have been found, it is referred
to that horizon on these grounds alone. It is the highest bed of the
lower Cretaceous in this locality.

UPPER CRETACEOUS.

The Vol Verde Flags. — The lower Cretaceous materials continue to a
point 2$ miles south of Del Rio, where the Vola limestone is overlain
by a softer flaggy limestone. The contact observed in this locality
was so small in area and so covered that no conclusion could be reached
regarding the conformity of the two beds. Where it has been observed
in other localities it shows little, if any, unconformity. The lime flags
can be followed to Sacatosa creek, 6 miles southeast of Del Rio, where
they are well developed. They are grayish-white in color, laminated to
flaggy in structure, and separated into bands by laminated clays. The
lower strata contain considerable bituminous matter and the remains of
fishes. The higher beds of this locality are also sufficiently bituminous
to give off a fetid odor when struck with a hammer. The principal
fossil here is TnoceramibS, "the species of which have not yet been de-
termined. These flags can be followed from this locality down Saca-
tosa (?) creek to the Rio Grande, and down the Rio Grande to Syca-
more creek, forming a bluff 25 to 75 feet in height along the river the
entire distance, so that we have an exposure some six miles in length
alonir the line of section, with a dip apparently not less than 100 feet to
the mile.

These Mull's are in Y;il Verde county, and for that reason I have
named the flags the Vol Verde Jim/*. They are tolerably uniform in
structure from base to top, the principal variation being in thickness.
In places they are shalv. but are COmmOnly flags of various thicknesses,
frequently showing on a transverse surface alternate parallel lamina' of
white and yellow. Their weathered surfaces are from Light yellow to
reddish, and in some places beds of deeper yellow or even orange hue are
found. Modci-atc amounts of oxide of iron occur, and at one place a
quantity of calcite was observed crystallized similarly to that which L

222 E. T. DUMBLE GEOLOGY OF THE RIO GRANDE.

have described from Anderson county.* In some localities, especially on
the Mexican side, the ferruginous coloration appears on the flat surfaces
of the flags in beautiful grainings, many specimens of which can he
seen in Eagle Pass and Porferio Diaz. The only fossils which I found
were different species of InOceramus, except toward the top Avhere a few
small ammonites were seen ; but it is possihle that others may he
obtained on closer examination.

A thin seam of lignitic matter was observed in the flags at the mouth
of Sycamore creek, on the southern side of the bluffs.f

The Pi lib) lame-stone. — Sycamore creek flows at the base of the Val
Verde bluffs, which at its mouth turn sharply northeastward and, after
running hack from the river for several miles, turn southeastward again,
and then run back toward the river, leaving a valley along the Texas side
some 4 miles or more in width. At the southeastern point of the bluff
on Sycamore creek the contact of the Val Verde flags with the base of
the overlying chalky limestone is found. The difference in the physical
character of the two limestones is very marked. The flags show their
laminated character throughout, while the overlying limestone is of
earthy texture and without any perceptible lamination. The beds' of
the upper limestone vary in thickness from one to three feet or more and
are separated by bands of laminated limy shales. The thickness of the
overlying limestone at this point is not more than 12 or 15 feet. The
fossils observed belong to the genera Tnoceramus and Ammonites.

These bluffs, in common with all others in this vicinity, are capped
with 20 to 30 feet of gravel or chalky conglomerate belonging to the
Reynosa beds.

Crossing the valley we find the bluffs at its southern margin on Pinto
creek to he of chalky limestones separated by limy clays in bands from
one to two feet in thickness, the whole exposure being about 30 feet in
height. The only peculiarity noticed was numerous grooves cut in the
limestone, extending diagonally across the present creek bed and very
nearly in the general direction of the flow of the Rio Grande,

On the Mexican side of the river, between these two points, a long
line of bluffs appears, showing the limestone resting on the flags with
apparently a slight difference in dip between them, the dip of the flags
being seemingly somewhat greater than that of the overlying limestone.
At the southern extremity of this line of bluffs the limestone is in
heavier beds (three feet or over) and rises to a height of 40 feet or more
above the river. Some cavities of considerable size have been weathered
in it.

*2d Ann. Rep. Geol. Surv. of Texas, 1890, p. 305.

■(•Mr. Owen informs me that these flags attain a very much greater thickness toward the south-
west in Mexico.

SECTIONS OF CRETACEOUS DEPOSITS. 223

Opposite the extremity of the line of biuffs, on the Mexican side and
a short distance above Piedro Pinto creek, the Rio Grande turns abruptly
westward, and for a quarter of a mile flows in rapids over the edges of
Underlying limestone. It is here that the water is to be taken out for
irrigating the valley north of Eagle Pass, which contains about forty
thousand acres of irrigable land. The exposures of the limestone con-
tinue from here to Las Moras creek, a total distance of 15 miles from
its first appearance. The following sections will show its character :

Cou- Creek Section.

Feet.

1. Thick-bedded limestones, with interbeddings of clay shales and nodules

of altered pyrites 40

2. Similar limestones in thinner beds 35 or 40

Fossils. — Inoceramus, Gryphsea, Ammonites, Baculites, of undetermined
species ; fossils sometimes ferruginated.

Texaquito Creek Section.

1 . Gravel, with calcareous cement (Reynosa beds)

2. Bowldery limestone containing numerous shells of Exogyra ponderosa,

Eoemer 6

.">. Chalky limestone f>

4. Softer limestones of similar character, with several species of Inoceramus

and other fossils 6

5. Yellow bowldery limestone in beds separated by bands of limy clay ;

the limestone becomes more chalky in appearance toward the base
(upper Gryphsea bed, characterized by Gryphsea aucella, Roemer,
which is very abundant toward the base, but disappeai"s toward the

top) 16

0. Harder limestone, much broken, with shales and limy clays 25

7. Obscured by later gravel 20

S. Limy clay, with great numbers of shells of Exogyra costata and Inoa -

mm us, sp. und

9. Yellow limy shales, with same fossils as number 8, and containing

ferruginous seam 4

in. Clayey limestone, with a large Ammonites (14 inches in diameter). Nau-
tilus, sp. now, and immense Inoceramus shells. This limestone is
bedded in strata twelve to fourteen inches in thickness and strongly
jointed. The compass bearing of join! planes is \". 20° E., and the
lines contain oxide of iron. The Inoceramus here, :is elsewhere, i^
preserved in two ways: In one they are simply molds showing the
outer form of one ur both shells; in the other, sljell fragments and
sometimes entire shells occur. Specimens were measured having a
Length of i;> inches 25

/."* Minns Section.

1. Gravel, chalky limestone, with some iron pyrites. Inoceramus of several

species, Nautilus, Ammonites, Baculites, etc., to creek \

22 I E. T. DCJMBLE GEOLOGY OF THE RIO GRANDE.

This .section is at road crossing of the creek, half a mile from the Rio
Grande. At the mouth of the creek the limestone passes under the
water, and just below is succeeded by the beds of the Eagle Pass divis-
ion. The contact is covered by river drift, but may be found further
up the creek.

Throughout the entire range of this chalky limestone the conditions
of deposition seem to have been quite similar. The beds become
somewhat more massive but broken toward the top. They are sepa-
rated by limy shales at the base, then by calcareous clays, then by
purer clays, and finally by calcareous clays again. Inoceramus and
A in mi miles seem to be the only fossils ranging entirely through the
Yal Verde flags and Pinto limestone, and the occurrence of Exogyra
ponderosa and E. costata so far down in the Pinto limestone is worthy of
note.

The Eagle Pass Division. — Immediately overlying the Pinto limestone
there is a great series of clays, sands and greensands, with more or less im-
pure limestone and beds of coal, to which I propose to give the name Eagle
Pass division. This name was suggested for a portion of these deposits
by Dr. C. A. White in 1887, and I now extend it to cover the entire
series of deposits lying above the Pinto limestone and below the Webb
bluff beds. It has a surface exposure along our line of section of nearly
sixty miles. It comprises a number of more or less distinct members
which may be described separately.

Upson Clays. — The basal member consists of yellow clay containing
calcareous nodules of septarian character, the crevices or septa? of which
are filled with dogtooth spar. These nodules occur in large geodic forms
scattered through the clays, and contain Exogyra, ponderosa, Roemer.
Numbers of specimens of these fossils are found in geodes as well as on
the hillsides, where they have been left by the disintegration of their
matrix. The nodules or geodes seem to occupy pretty definite horizons,
and sometimes form benches on the hillsides. The uppermost member
of this series, as I observed it, is a clay shale.

San Miguel Beds. — Resting on the clay shales, which form the upper
member of the Upson clays, there is a deposit of sandstone, thin to heavy
bedded, separated by bands of clay, and containing seams of glauconitic
material with many fossils, as well as occasional heavy beds of clay,
especially toward the top. I have called this deposit the San Miguel hols
from the locality at which it was first observed by Dr. Comstock and
myself. In the Rio Grande section it first occurs in the hills north of
Carter's ranch, where the hills show exposures of it from 75 to 100 feet
in height. The exposures are excellent for several miles south of this
point, and a very rich fauna, which is now being studied, was secured.

SECTIONS OF CRETACEOUS DEPOSITS. 225

In the upper portion I found Exot/j/ra ptinrfn-oxa, and great numbers of
other shells not yet determined. Above this the sandstone becomes
more calcareous, and in places is compacted and contains calcareous
nodules. Three miles south of Carter's ranch we found the teeth and
bones of a saurian in the concretions. The materials overlying this
become more clayey, as will be seen by the following section, made some
10 miles north of Eagle Pass :

Section near Eagle Pass.

Foot.

Sand and silt 8

Sandstone 2

Clays displaying cone-in-cone structure <>

Sandstone with laminae and nodules of calcite 1

Clay, to base 8

Above this there are sands with lime and greensand containing man}'
casts of fossils, Inoceramus and other bivalves, together with numerous
gasteropods. This continues to a point about 8 miles north of Eagle
Pass, below which these strata are soon covered by the next newer series
of deposits.

The Coal Series. — This series comprises the ferruginous shales, brown
calcareous shales, brown calcareous clays, heavy bedded sands, shales,
sands, and yellow clay which accompany the coal seam worked at the
Hartz and other mines.

The exposures along the river above the Hartz mine show the following
strata underlying the Reynosa beds of gravel and limestone :

Section near the Hurt: Mine.

Feet,

Brown calcareous clays 40

Ferruginated shales 40

Uncompacted sands* 20

Shale 20

Heavy bedded sands 30

Yellow clayf 20

( !( .alf 4

Purple shalef 6

Sam! to riverf

Just south of the Hartz mine there may he seen the only disturbance
of any considerable extent which was noticed in the entire section north

* Western extremity "i coal seam,
I E \ posed just above ll.nl z m inc.

226 E. T. DUMBLE — GEOLOGY OF THE RIO GRANDE.

of Eagle Pass. This is a fault with a downthrow toward the north of
about 60 feet.

Half a mile below the bridge across Elm creek the following section
was observed :

Section on Elm Creek.

Feet.

Sand 12

< iravel 1 to 4

X( idules of oxide of iron 5 to 1

Sand 2

Chocolate clays, with interbedded iron nodules 3

Cross-bedded sandstone 1

Blue clay 1

Sandstone containing clay inclusions, some glauconite, and regularly stratified

iron nodules 3

( "lavs with very thin seam of coal

Above the bridge a deposit of shaly sands occurs, containing ferru-
ginous sandstone seams which in -places pass into a lean iron ore and
form a stratum of eight to twenty inches in thickness. The sandstone
has a very shaly appearance on weathering. Overlying this there are
beds of laminated yellow clays, followed by darker beds with a very thin
scam of coal.

Immediately above the laminated clays lies the stratum containing
cannon-ball concretions, which, with the overlying sands carrying great
quantities of silicified wood, form one of the most persistent and easily
recognizable horizons of the series. There are numerous excellent expo-
sures of the latter on Seco creek.

Convent Hill Section.

Feet,

Gravel (Reynosa beds)

Yellow clays and sands 30

Calcareous nodules, highly ferruginous, imbedded in clay 1 to 2

Bituminous shales with ',-inch seam of coal, to river

Above these beds are found a series of brown or buff sandstones, semi-
indurated, calcareous, and containing fossil shells of Tnoceramus, Exogynt
ponderosa, etc.

The entire section from these sandstones to the lower San Miguel
sandstones is shown in a general way in the following record of a boring
made for artesian water on the top of the hills just northeast of Eagle
Pass :

THICKNESS OF CRETACEOUS DEPOSITS. 227

Eagle Pass Artesian Well Section.

Feet.

1 . S< >il and subsoil 14

2. Yellow clay 26

3. Bluish clay 50

4. Sand with some gravel 110

5. Black shale ; six inches coal 60

6. Clayey sand 70

7. Gray sand 30

8. Sand ; small gravel 60

9. Sand 20

10. Gray slate 30

1 1 . I >ark shale 55

12. Coal 6

1 3. Dark shales !)

14. White sand ; gas 40

15. Black shale 150

16. Sand and shale 15

17. Black shale 135

18. Sand and shale ; gas 15

19. Dark soft sand and shale 75

20. Hard gray sand ; salt water 10

21. Gray shale 50

22. Gray sand 10

23. Calcareous clay 370

24. Dark clay 102

Total 1,512

This is important as giving us the relative dip of the beds. The coal
seam which crops out 5 miles above Eagle Pass is found here at a depth
of 525 feet, while at 1,512 feet the heavy sandstones which were noted 3
miles north of Carter's ranch, or 15 miles above Eagle Pass, have not
yet been reached. The estimate of dip at 100 feet to the mile is there-
fore seemingly not at all excessive.

The materials below Eagle Pass are somewhat different from those
above. The sandstones are harder and the clays have a blue or greenish
hue; the lime, instead of being in the form of geodes or septaria, is
intermingled with the sand, or forms separate strata; and the fossils are
much more plentiful than in-any other division except the San Miguel
beds. I propose to call this deposit the Escondido beds.

Escondido Beds. — The last exposures <>f the Coal series beds on the
river are at Porferio Diaz, where a greenish sandy clay with glauconite
was observed, and a mile below, on the same side of the river, where there
is a similar bed of sandy clay with indurated bowlders, streaks of lignite,
im press ions of Leaves (grasses), and logs of silicified wood. At the mouth
of Escondido river similar clay was seen, and a mile below there was
XXX— Bull. Geol. Soc. A.m., Vol, :'•, 1891.

228 E. T. DUMBLE GEOLOGY OF THE RIO GRANDE.

found a series of sandy clays capped by sandstones, with an indurated
glauconitic layer containing small oysters and other fossil forms. This
sandstone is the same as that capping the hills at Eagle Pass and is the
lowest stratum of the Escondido beds.* Passing down the river this
sandstone thickens and shows ripple markings in places, and has an
apparent dip of at least 2°. The exposure is a mile in length, and con-
sists of sandstones alternating with clays. Fossils are very abundant
and well preserved, consisting of Ammonites (Placenticeras), oysters and
other bivalves, and several gasteropoda. Similar exposures continue for
4 miles below Eagle Pass. Above these come other blue clays and thin
sandstones with many oysters.

At Fortress bluff, 6 miles below Eagle Pass, the exposure has a height
of 60 feet, and is composed of sandstones with seams of sandy clay
interstratified. The first of the great oyster beds occurs here in strata
six inches to a foot in thickness. Similar exposures continue to the
bluffs 10 miles from Eagle Pass. The sandstones at this locality are
highly calcareous and contain several beds of oyster shells.

From this point to the falls of the Rio Grande, just above the Webb
county line, the exposures are but repetitions one of another — brown.
buff, blue, or green clays, with sandstones, sometimes friable and some-
times so indurated as to be semi-quartzites. Abundant fossils, consisting
of Ammonites (Placenticeras), oysters and gasteropoda, are found. The
rapids (or falls of the Rio Grande), which continue almost to the line
between the two counties, are formed by the edge's of some of these
ammonite-bearing beds as they pass below water level. From this point
to Webb bluff, a distance of 3 miles, no fossils were found ; but there was
no change in the lithologic character of the rock materials, nor could
the clays at the base of the Webb bluff section be distinguished in any
way from those observed at the rapids above.

Webb Bluff Section.

Feet.

(xiavel ,

Sandstone, white and glistening, with mica and some little iron; calcareous
sandstones; clay with cannon-ball concretions; and small seam of gra-
hamite MO

Greensand marls with many Tertiary fossils; nodnles of carbonate of lime;
specks of glauconite 7 to 8

Stiff, plastic dark greenish or bine clay, jointed 10

We have therefore only •'{ miles in which there can be any room for
deposits intermediate between strata containing fossils of recognized and

♦From Mr. Owen's examinations I learn that this is a very persistent bed throughout Maverick
county and is easily recognizable. It is about rive hundred feet above the coal seam, and is there-
fore valuable as a definite horizon from which to work in prospecting for the coal.

ATTITUDE AND THICKNESS OF THE DEPOSITS. 229

decisively marine Cretaceous forms and those containing marine Eocene
forms. The average dip does not exceed 100 feet per mile, and we saw-
nothing in any of the exposures on either hank of the river in this space
to indicate a change until we reached Webb bluff itself. The entire
appearance of the upper portion of this bluff was so different from that
of the materials we had been examining for the three previous days
that it was remarked even before we landed.

The upper Cretaceous Section. — If the estimated dip of 100 feet per
mile can be relied on (and no evidence was found in the field work to
cast any doubt upon it) the section as given would have a total thick-
ness of over eight thousand feet, of which the upper Cretaceous deposits
constitute about 7,800 feet, divided as follows :

Feet.

' Escondido beds 3,300

^ , t. t • • Coal series 901 >

Eagle I ass division - ^ Migud bedg m

[ Upson clays 700

Pinto limestones 1 ,500

Val Verde flags 600

SI )( i

It may not lie prudent, however, to rely implicitly upon the apparent
dip in such materials as form the Escondido beds, because faulting might
occur in places and be entirely unnoticed in such an examination as we
could make. It is therefore possible that future work may somewhat
reduce the estimate here given.

REYXOSA BEDS.

In May, 1880, I observed along the line of the Southern Pacific rail-
way between San Antonio and Eagle Pass a deposit usually consisting
of a larger or smaller quantity of gravel cemented by a very porous or
tufaceous limestone. In some places the gravel seemed to be entirely
missing and only the limestone present. The same deposit was noticed
north of Eagle Pass on our visit to the coal mines, and we found it
forming the summits of the hills at many localities along the river
during our voyage from Eagle Pass to Edinburg. The thickness of this
deposit as noted was from 3 to 30 feet, and in some instances it was
overlain by the yellow silt flanking the Rio Grande. At the town of
Reynosa (in the Mexican state of Tamaulipas) and opposite Edinburg
in Texas we found a much larger and firmer deposit of limestom — the
same indeed which was designated in the report of the Mexican boundary
survey Cretaceous limestone. Our examinations resulted in finding

230 E. T. DUMBLE — GEOLOGY OF THE RIO GRANDE.

in it such fossils as Bulimus altematus, Say. and in showing that it is
stratigraphically higher than the Fayette sands. Dr. Penrose described
it in the first annual report of the geologic survey of Texas under the
name of the Reynosa limestone. The connection between this Reynosa
limestone and the tufaceous lime and gravel, however, was not recog-
nized until the past summer. Mr. J. A. Taff of the Texas survey, in his
examination along the line of the Texas-Mexican railway between
Corpus Christi and Laredo, observed the same lime and gravel with
Bulimus altematus overlying the Fayette sands at various places. I
joined his party in Cotulla, and during my work with them up the
valleys of the Nueces and henna rivers I found many exposures of the
gravel and lime and of the firmer limestone already described in such
connection as to prove conclusively that they are mere local variations
of one and the same deposit. I therefore extend the name Reynosa to
include the entire series of deposits for the present. These deposits
cover a very large area in western Texas and extend into Mexico. In
places the limestone reaches such thickness and hardness as to be used
as building material, as in the district south of Porferio Diaz, at Rey-
nosa, and elsewhere. As nearly as we have been able to ascertain, these
beds seem to be in part at least the equivalents of the Equus beds
described by Professors Cope and Leidy in southwestern Texas. They
appear to rest unconformably upon the underlying beds of Cretaceous,
Eocene and Neocene age. While the connection of the Reynosa beds
with the Lafayette formation toward the east has not been determined
by actually tracing one into the other, their similar stratigraphic position
above the Fayette sands and beneath the coastward clays of the Port
Hudson (Columbia formation of McGee) is strong evidence in favor of
their being different phases of the same formation.

CORRELATION OF RIO GRANDE AND COLORADO RIVER SECTIONS.

Rio Grande Section. Colorado Section.

Neocene Reynosa beds Lafayette (?)

Eocene Webb Bluff Tertiary Eocene

( ( Escondido beds. . . . (Wanting i

I Eagle Pass ! Coal scries (Wanting)

rT ., division I San Miguel beds . ... Glauconitic beds

1 PPer Cretaceous^ [ Upson days Ponderosa marls

j Pinto limestone Austin limestone

I. Val Verde flags Eagle Ford shales

r ,, ( Vola limestone Vola limestone

Lower ( retaceous j Jr/. //;)„ dayg ^ ,,-,„ clayg

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 231-252, pl. 7

ELEOLITE-SYENITE OF LITCHFIELD, MAINE, AND HALVES1

HORNBLENDE-SYENITE FROM RED HILL,

NEW HAMPSHIRE

W. S. BAYLEY

RO< HESTER

PUBLISHED BY THE SOCIETY

June, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP. 231-252, PL. 7 JUNE 4, 1892

ELEOLITE-SYENITE OF LITCHFIELD, MAINE, AND DAWES
HORNBLENDE-SYENITE FROM RED HILL, NEW HAMP-
SHIRE.

BY W. S. BAYLEY.

{Brad before the Society December 31, 1891.)

CONTENTS.

Page

I nt rod net inn 231

The Eleolite-Syenite of Litchfield and other Localities in Maine 232

I (istribution 232

Macroscopic Description '■'>'■'• 4

Microscopic Description 235

Discussion and Summary 241

Hawes' Hornblende-Syenite from Red Hill, Moultonboro, New Eampshire. . . 243

Historical 243

( Occurrence 244

Macroscopic Description 244

Microscopic Description and Discussion of Chemical Analyses 245

Summary 250

Introduction.

Of the two rocks whose petrographical descriptions arc here given, one
is from the well known occurrence near Litchfield, in Maine and the
other is the rock described by Hawes* as a hornblende-syenite from
Red Hill, Moultonboro, New Hampshire.

In neither case has the writer examined the geological relations of the
rocks sufficiently closely to warrant an expression of opinion regarding
them. The New Hampshire locality has not been visited at all. The
.Maine occurrences have been visited twice, hut on neither occasion were
more than a few minute- spenl at the several places where the rock is
found.

The only excuses for the publication of this fragmentary paper at the
presenl time are the interest thai always pertains to the rare eleolite-

*G.W. Hawes: Min. and Lith. of Ne\\ Hampshire, p( iv of Geology of Now Hampshin I
1878, p. -M"',.

XXXI I'.i i i '.,,., Soi \>i \ 01 I 1801 ;| '

232 \Y. S. BAYLEY — SYENITES FROM NEW ENGLAND.

syenites and the desire to ]>ut on record the discovery of another locality
for them within the United States.

Thanks are due to Messrs II. K. Morrell of Gardiner and R. G. Clough
of Monmouth, Maine, for valuable aid in the collection of specimens of
the Maine rock, and to Mr. M. M. Smith of Deland, Florida, and Mr.
W. If. Mason of Moultonboro for information respecting the New Hamp-
shire locality and for abundant material from it. Mr. J. S. Diller and
Dr. F. W. Clarke of the United States Geological Survey have also done
all in their power to help make the descriptions as complete as possi-
ble under the circumstances, the former gentleman having furnished
thin sections of both the Maine and the New Hampshire rocks, and the
latter having kindly provided analyses of both, f desire to express my
appreciation of their aid, and also to thank Mr. G. P. Merrill of the
National Museum for a chip from FfaAves' original specimen of the New
Hampshire rock, and Messrs L. G. Eakins, W. H. Melville and W. F.
Hillebrand for the careful chemical work that appears in the body of
this article.

The Eleolite-Syenite of Litchfield and otiifi; Localities in Maine.

Distribution. — ft is not quite certain that this rock has been found in
place. Nearly all the specimens that have been sent abroad to the
museums of this and other countries have come from bowlders or loose
fragments lying on both sides of the road running from South Litchfield
post-office, in the town of Litchfield, Kennebec county, Maine, to the
city of Gardiner, on the Maine Central railway, about six miles south of
Augusta. The distance of the locality from South Litchfield is about
three-quarters of a mile, and from ( rardiner about eight miles. Here the
fragments and bowlders are often quite large. Some are half buried in
the soil on the gradual slope of a hill, while others lie on the surface.
From the great abundance of the bowlders and their large size, together
with their thick accumulation in such a small area, it is argued by many
competent geologists that the parent ledge is somewhere in the near vicin-
ity. However this may be, there can be no doubt that the rock is a schistose
eruptive. In large pieces the schistosity is quite apparent, and even in
hand specimens it may sometimes he readily detected. The character-
istic mineral of this occurrence is cancrinite. The other two localities in
which cancrinite predominates over sodalite and eleolite are southeast
of South Litchfield, on the farms of Messrs Sawyer and Spaulding (see
map, figure 1). In both of these cases the rock is in the shape of bowl-
ders. At Sawyer's several large ones lie on the surface south of the road
and within sight of it ; at Spaulding's broken fragments are found built
into stone walls. The underlying rock at both places is quite different

GLACIAL DISTRIBUTION OF ELEOLITE-SYENITE.

from the eleolite-syenite, so that there is no probability of the latter be-
ing found at either place in situ. On the other hand, it is worthy of
remark that the bowlders in both instances are directly in the course
of the glacier* that passed over the region of South Litchfield.

Another well known locality, especially for that phase of the rock
containing sodalite and Large crystals of eleolite, is at Spears Corner, in
West Gardiner, on the road from South Litchfield to Gardiner. On the

FiouttEl— Map showing Distribution of Eleolite-Syenite in thi Town oj Litchj la IV tGardiner,

Mai i

northern side of the road and aboul one hundred yards from it. in a
clump of bushes near the bottom of a hill, there is a pile of Large blocks
resembling in their genera] arrangement the heap ;it South Litchfield.
Mosl of these were originally completely buried in the sand and soil
They are now well exposed through the active operations of collectors,
hut the soil around them has not been sufficiently removed to enable us

»Cf. T. C. Chamberlin: Map of a Portion of the Terminal Moraiuo, in 3d Ann. Rep. 1 -
Survi

234 W. S. BAYLEY — SYENITES FROM NEW ENGLAND.

to say positively whether the rock exists merely in bowlders or whether
some of it may not be in place. A little north of east of South Litchfield
the sodalite-bearing eleolite-syenite is again met with, on the eastern
slope of a glacial ridge on the western side of the southern end of Coch-
newagon pond in the town of Monmouth. Mr. Clough, who has carefully
explored the region thereabout, asserts that the rock is found in a stretch
of country running about northwest and southeast, with a width of only
a few rods and a length of about two miles. Within these limits bowl-
ders may be picked from any of the stone walls surrounding the tiel<!>-
Beyond them the syenite has not yet been discovered. At Cochnewagon
pond the bowlders of eleolite-syenite occur in considerable numbers
with others of gneiss, granite and schist, principally at the base of a
gravel and sand ridge that rests upon a foundation of slate. There is no
question but that in this case the rock is not in place. It lias undoubt-
edly been transported thither from somewhere toward the northwest*

From a consideration of the statements above made, it would seem
probable that all of the eleolite-syenite of the towns of West Gardiner,
Litchfield and Monmouth has come from a region beyond the limits of
these towns, and that nowhere within them does the rock occur in place.

Macroscopic Description. — The macroscopic- appearance of the Maine
eleolite-syenite is too well known to need much description. Its most
noticeable features are the large masses of bright yellow cancrinite and
deep blue sodalite and the brilliant plates of black mica that spot
its otherwise almost snow-white surface. Here and there light brown
zircon f crystals are imbedded among the other constituents, but they
are by no means so numerous as museum specimens would seem to
indicate. Among the lighter minerals that can be distinguished in the
hand specimen, the most abundant is a white feldspar, often occurring
in large columnar crystals from a quarter to a half inch in length. They
have a distinct cleavage and a pearly luster on cleavage surfaces. Their
specific gravity varies between 2.608 and 2.600. A partial analysis of
pieces picked from a hand specimen is reported by Dr. Clarke J to have
yielded —

SiOz

AU »;,

K,()

Xa,< )

H,0

Undet

66.39

19.69

0.99

10.17

0.52

(2.24)

This feldspar, which is undoubtedly albite, is the most prominent one
in the rock, and is that which gives to it its characteristic peculiarities.

- ni the eleolite-syenite, sometimes containing cancrinit ■ and al other times rich in
sodalite, may also be found in almost any of the stone walls dividing tin/ fields that lie within an
area encompassed by lines joining (lie above described points.

j-These zircons were analyz :d by Gibbs (Pogg. Annalen, b. Ixxi. 1822, p. 559) with the following
result: Si03= 35.26; Zr02 = 63.33; Fe»03 = .79; undet. = .36.

I Ain. Jour. Sci., 3d ser., vol. xxxi, 1886, ]>. 'jnS.

COMPOSITION OF ELEOLITE. 235

Another of the prominent components is eleolite, which appears as
irregularly shaped masses or as large columnar crystals with a length of
as much as two inches and a breadth of halt' an inch. The irregular
masses are distributed uniformly throughout the rock, while the crystals
occur only in those portions in which the darker constituents are lacking
( i. <>., in acid " Schlieren v). In both cases the mineral possesses a gray
color and the characteristic oily luster of eleolite, while its cleavage
cracks are marked by interpositions of long dark needles of a black mica.
Dr. Clarke* reports the eleolite to contain —

Si02 ALA CaO MgO K20 Na,<) II,<> Total

13.74 34.48 tr. tr. 4.55 16.62 0.86 100.25

All the constituents above mentioned are usually imbedded in a fine
sugary aggregate of feldspar, of which there are several varieties, as will
he shown later. Occasionally this fine grained aggregate is in very large
quantity, when it appears as a groundmass surrounding the coarser
grains. More frequently it is in smaller or larger areas between the other
components, and in rare cases it is entirely absent. In this latter event
the rock is a coarsegrained mixture of large albite and eleolite grains
and plates of lepidomelane. Its structure is massive, while that of all
other varieties is schistose. In these schistose phases the plane of schis-
tosity, as shown by the lamellar arrangement of the mica plates, is par-
allel to the contact of the rock with a lepidomelane schist, that is prob-
ably nothing other than a very basic portion of the rock magma that has
been rendered schistose by pressure. In thin sections of all specimens
in which the schistosity is marked, the foliation is plainly seen to be due
to pressure; for not only are the feldspars marked by many series of
curved twinning lamellae, but the rock is also shattered, and in the cracks
separating its different portions a large quantity of new feldspar has been

deposited.

Microscopic Description. — The texture as revealed by the study of thin
sections is thoroughly granitic, in that nonef of the components possess
crystal outlines, though many of the eleolite grains and some of those of
the albite have quite well defined rectangular cross-sections. With the
exception of the rare zircon, the lepidomelane is the oldest constituent,
l.ut whether this is followed by eleolite or albite it is difncull to deter-
mine, since in mosl cases the eleolite and the larger grains of albite
are separated by areas of finer grained feldspars that are certainly
later in origin than either one of the two minerals mentioned. It is

*Ibid., p. 262.

; ih i -i,, i imeni applies only t" the main m iss of the rock, and is nol true » il h regard to il
or basic aggregations ("Schlieren"), where crystals of olcolite oi of lepidomelane are nol un
common.

236 W. S. BAY.LEY — SYENITES FROM NEW ENGLAND.

probable, however, that the eleolite preceded the plagioelase in its
crystallization.

The only dark colored component visible is a dark green biotite,*
present not only in the large plates already mentioned, hut also as in-
clusions in the eleolite. In basal sections the mineral is so dark as to be
almost opaque. In other sections the ray vibrating perpendicular to the
cleavage is bright greenish-yellow, while that vibrating parallel to the
cleavage is dark green. The absorption, therefore, is a <L h = C. The
apparently uniaxial, negative interference figure opens slightly when
revolved under crossed nicols, and the extinction of the mineral is some-
times inclined to the cleavage about 1°. The composition, according to
Clarke,t is that of a very basic lepidomelane :

Si02

A1,03

FeA

FeO

MnO

Ca( >

K,0

Na.,0

H,0

Total

32.35

17.47

24 22

1341

1.02

0.89

(1.70

6.40

4.67 =

= 100.83

In natural light the mass in which the lepidomelane is imbedded
appears as a colorless matrix, lor the most part transparent, but clouded
here and therewith opaque white and yellowish decomposition products

of eleolite and the larger albites I figure 1. plate 7). Under crossed nicols
this apparently homogeneous groundmass resolves itself into large dull
grains of eleolite and albite, and a finely granular aggregate of brilliantly
colored feldspars and cancrinite, and a few perfectly isotropic grains of
sodalite.

The eleolite. although it sometimes has a rectangular cross-section, is
usually in allotriomorphic grains, whose outlines arc rendered more or
less jagged by projections extending out into the areas between the sur-
rounding grains. The inclusions that crowd it are glass and fluid cavi-
ties, the latter frequently containing movable bubbles, long narrow plates
of lepidomelane, with their longer directions parallel to the vertical axes
of their host.-, and various decomposition products, among which may
he mentioned a few brightly polarizing fibers of some zeolitic mineral
and an occasional Hake of muscovite. Sodalite and cancrinite were also
met with, in a single instance, as alteration products of the eleolite; hut
since they were not entirely inclosed by this mineral they can scarcely
he spoken of as inclusions. Under crossed nicols many of the larger
grains are discovered to be intergrown with a twinned feldspar, which,

* In spite of earn esl search through sixteen sections of the Litchfield rock, no trace of any mica
hut this could be discovered although both Rosenbuseh (Mikroskopische Physiographie, b. ii
L887, p. 85) ami Clarke (Am. Jour Sci., 3d ser., vol. xxxiv, 1887, p. 134) mention the exist snee of two
micas in it. In one section of tin- Cochnewagon rock the biotite is dark bi-own instead of dark
green. It presents tin' pleo shroism of ordinary biotite, and is certainly ao( a lepidomelane. The
rock is much decomposed, and is different in so many of its features from tin- other specimens
collected at this place, as well a- at the localities in Litchfield a in I West < rardiner, that its consid-
eration is entirely omitted from the present discussion.

fAm. Jour. Sri.. 3d ser., vol. xxxiv. l.s.sV. p. 133.

FEATURES OF THE FELDSPARS. 237

judging from the mass-analysis of the rock (page '241), must be albite.
.Many small areas of this inclosed feldspar occur with their axes in the
'same direction. Their material is not sharply defined from the surround-
ing eleolite, but appears to pass into it by insensible gradations.

Of the feldspars the most abundant is the cloudy albite occurring in
the columnar crystals already mentioned. In the thin section these
possess long f|uadrangul ir forms, characterized by a series of remarkably
fine twinning lamellae, whose close study affords the best evidences of
the pressure to which the entire rockmass has been subjected. Indi-
vidual twinning plates often wedge out and disappear, while others spring
from the sides of cracks. Other lamella? are bent and bowed, some are
broken off sharply at cleavage cracks, while still others in the interior of
the grains are crossed by a second series of striations running nearly at
right angles to the first ones. There are also indications that some of
these grains are composed of two feldspars, for their resemblance to
Brogger's * pictures of cryptoperthite and microcline-microperthite is very
striking. The character of the two feldspars, however, has not been cer-
tainly established, though it is quite probable that albite and microcline
form one of the combinations. The specific gravity and composition of
these albites have already been given (page 234). Since they contain but
one per cent of K20 it is quite clear that the potash molecule cannot
play a very great role in the intergrowths.

The difficulty in determining the true nature of the constituent feld-
spars in these combinations is due principally to the fact that the large
grains are penetrated in all directions by jagged embayments of a pellucid
plagioclase with broader twinning lamellae than those of the turbid pheno-
crysts and without inclusions of any kind. Small areas of this glassy
feldspar occur all through the large albites, so that the latter appear to
be completely saturated with the former. The saturating feldspar often
has two sets of twinning striations. It polarizes in gray and blue tints,
and always has ragged outlines when it does not grade into the enclosing
albite. It seems impossible to assign any but a secondary origin to the
included material. The Large crystals arc so corroded by it that in some
cases but a slight film of the original substance separates the different
areas of the new substance from each other. ■ The different areas of the
new feldspar, moreover, are optically continuous with one another, as
are also d ill ei-en t poi-t ions of the enclosing albite, so thai the polarization
of the intergrowths is very like that of quartz and orthoclase in micro-
pegmatite.

besides this saturating feldspar there are other feldspars occurring in
small grains, in some instances forming a sort of mosaic in which all the

i W, C. Brogger: Z.n-. f. Kn-i b xvi, 1890, taf, xxii, fig 3,nnd taf. xxiii. liir. I.

238

W. S. BAYLEY SYENITES FROM NEW ENGLAND.

other components of (lie rock lie, and sometimes filling what were appar-
ently cracks in the rock mass (figure 2, plate 7). All these grains polarize
with bright colors, and all arc clear and perfectly transparent. They are
all of about the same size, none ever have crystallographic outlines, and
all are younger than the large crystals of albite that have been mentioned
st> frequently. In rare cases this mosaic itself is imbedded in a finer
mosaic of the same character, except that it is saturated with cancrinite.
The structure produced by the imbedding of the larger components of the
rock in this fine grained mosaic is strongly suggestive of the mortar
structure of Tornebohm, which is regarded by this author as a certain
indication that the rock exhibiting it has been subjected to pressure and
shearing.

Two feldspars are distinctly observable in the mosaic, and a third one
may exist. The two undoubtedly present are so much alike in appearance
that it is difficult in many instances to determine the nature of a par-
ticular grain. The number of untwinned grains however indicates the
presence of an orthoclase, while t lie number of grains with straight narrow
twinning lamellae points to the existence of a plagioclase. Another feld-
spar almost surely present is microcline. It is in slightly larger pieces
than the other two. and is well marked by the double twinning. It is
impossible to speak more positively as to the nature of these feldspars, as
cleavage cracks are not common, crystallographic outlines are never
present, and tin1 twinning lamella; are bowed and bent to such an extent
that readings of extinction angles are not decisive.

In separation by the Thoulet solution two lots of feldspar fell when the
density of the liquid was 2.022 and 2.56 respectively. That which fell
at 2.G22 consists of grains usually striated in a single direction and of
others in which no striations arc noticeable. The latter extinguish at
19° from the cleavage, and show between crossed nicols the bar of an
axial figure. Their analysis, made by Mr. W. H. Melville, of the United
States Geological Survey, is that of a very pure albite (I) :

Albite.

II.

( >rthoclase.

SiO

68.28
19.62

.-_»:;

.31

.09

..",9

10.81

.09

68.62
19.56

(15.14

18.19

.25

qq
.OO

.10

14.14

1.1 is
.17

<;i o

Al.,<">..

1 S .")

FH )

CaO

MgO'

K.,( )

L6.9

X.'cO

1 1 .82

B,0

99.82

100.00

100.06

100.00

GENESIS OF THE LITCHFIELD ROCK. 239

The powder that fell at 2.56 contains some untwinned grains and many
with the twinning striations of microcline. Its composition is given under
column II. As will be seen by comparison with the figures for ortho-
elase, this mineral also is very pure. There can be no doubt that it is a
potassium feldspar, and it is probable that it crystallizes in both mono-
clinic and triclinic forms.

In view of the fact that eleolite-syenite is defined as a rock consisting
essentially of orthoclase and eleolite, it becomes of importance to determine
whether the potash feldspars in the Maine rock arc primary or secondary..
It is very evident that they are younger than the eleolite and the large
crystals of albite, and are of the same age as the albite grains in the
mosaic. Their small grain, perfect transparency, lack of cleavage, and
the method of their occurrence in narrow stringers and small areas be-
tween the undoubted primary constituents point to a secondary origin
for all the minerals in the mosaic. The arrangement of these is, however,
somewhat peculiar, in that in nearly every ease they are more or less
lenticular and their long axes are rudely parallel to the long directions
of the areas which they form. This would indicate that the pressure by
which the rock was made schistose acted after the feldspar grains of the
mosaic were formed. The explanation of the phenomenon seems to be
that the rock which originally consisted of eleolite, albite, lepidomelane,
and perhaps some orthoclase or other feldspar, was subjected to great
pressure intended by motion, that it was broken and shattered, and
that the fragments were rolled upon one another, and at the same time
albite and orthoclase were deposited in all the crevices as they were
formed. The pressure and motion continued until all the newly formed
grains became oriented, and some had developed in them twinning
lamella'. From all the evidence at hand it would appear that the micro-
cline in the Litchfield rock is merely an orthoclase with secondary cross-
twinning.

An indication of the correctness of this view is the fact that where the
feldspathic mosaic is absent the rock is massive and not schistose — i. < ..
where pressure has not produced foliation there is an absence of the small
grains of feldspar composing the mosaic.

The only two constituents remaining to lie described are cancrinitc
and sodalite. The latter may usually he recognized by its lighl blue
color in natural light, though at times its tint is so pale that it can he
detected only by the contrast afforded by the colorless minerals associ-
ated with it, which appear to be slightly tinged with yellow, Under
crossed nicols it is perfectly isotropic. No idiomorphie forms occur, bul
the substance extends irregularly around the other components includ
iic: them, as augite does the feldspar in many diabases. The most abun-

\ \ X 1 1 I'.i i i 1. 1. ii Sin \ >i \ "i . ::. 1891,

240 W. S. BAYLEY — SYENITES FROM NEW ENGLAND.

dant of tho minerals imbedded in the sodalite are irregular grains of
plagioclase, little plates of lepidomelane and cancrinite, and a few small
Hakes of a brightly polarizing micaceous substance. Eleolite is often
intergrown with the sodalite in such a way that a large number of appar-
ently isolated areas of the former polarize together. The relation of the
sodalite to the other constituents leaves no doubt as to its age with respect
to these. It is certainly younger than any of them. Therefore, since it
is younger than components that are themselves younger than the eleo-
lite. and at the same time is intergrown with the latter mineral, as de-
scribed above, it must be an alteration product of this. The beautiful
pieces that have been sent to the museums as mineral specimens are cer-
tainly secondary, for in them the sodalite is found on the faces of joint-
cracks, and in most cases it extends back from these surfaces into masses
of eleolite that lie near them.

The composition of compact masses of sodalite taken from seams in
the Maine rock was found by Clarke* to be :

(0 = C1)

SiO.,

A1,03

Na20

K20

II.o

Total

.»- • >>>

31.87

24.56

0.10

6.83

1.07 =

100.22

The white alteration product of sodalite described by Dr. Clarke f under
the name of hydro-nephelite was not seen in any of the sections examined.
This is probably owing to the fact that the sections were all made from
pieces of the rock taken from the interior of blocks at some distance from
seams or joint cracks. Its microscopical description is so well given by
Diller J and Brogger,§ however, that little could be added to it by study
of material in the writer's possession.

The cancrinite is not distinguishable from feldspar in ordinary light,
except in thick sections, where it possesses a slightly yellowish tinge. In
thinner sections it is colorless, transparent and without inclusions, other
than pores containing liquid inclosing movable bubbles. Of these there
are two kinds, viz, a series of long quadrangular and spindle-shaped cav-
ities arranged in lines with their long directions parallel to the vertical
axes of the cancrinite grains, and round and irregularly shaped ones
running in lines that are usually sharply inclined (often perpendicular)
to these axes. Under crossed nicols the mineral polarizes with very
brilliant colors, and extinguishes parallel to the two well marked cleav-
ages that traverse it. The grains, which are all allotriomorphic and
elongated in the direction of the lateral axes, are found intermingled
with the feldspar of the mosaic and in larger pieces scattered between

* Am. Jour. Sei., 3rd ser., vol xxxi, 1886, p. 264.

t Lbid., p. 265.

t [bid., p. 266.

\ Zeits. d. Kryst.. b. xvi. L890, pp. 234 and 636.

COMPOSITION OF CANCRINITE. 241

the eleolites and the larger albites. Dr. Clarke,* arguing from the result
of his analysis of the mineral, declares that most of the cancrinite of the
Litchfield rock is an alteration product of eleolite ; while Rosenbusch,f
on the other hand, cites it as an especially fine example of primary can-
crinite. The microscope shows conclusively that some of the cancrinite
has resulted from the alteration of eleolite. The most of it, however, is
so far removed from eleolite that its relation to this mineral has not been
discovered. It occurs principally in the mosaic, which has been thought
to be of secondary origin, and is the youngest of its constituents, with
the exception of socialite. It has certainly crystallized from the magma
that yielded the other minerals of the mosaic, and in this sense is orig-
inal, but its chemical components may nevertheless have come from
some of the eleolite that was destroyed at the time of the formation of
the mosaic.

The composition of the commonest type of the cancrinite, the bright
yellow granular variety, is as follows :

AUG,

Mn.,< >3

Fe203

CaO

Na.2< >

K.,0

MgO

H20

CO,

Total

2S.82

tr.

4.40

19.48

0.18

0.07

3.86

6.22

= 99.70

Discussion and Summary. — A noticeable fact in connection with this
rock is the absence of sphene, hornblende and augite. The former is
present in nearly all normal eleolite-syenites, with the exception of those
from Kangerdluarsuk in Greenland and from Funfkirchen in Hungary ,|
while one of the last two is usually found, even though biotite be the
most prominent of the bisilicates present. Another fact of interest in
connection with the Maine rock is the great preponderance of albite
among the feldspars. An analysis of the most common phase of the
rock by Mr. L. G. Eakins gave:

Si< ).,

00.89

ALA

22.51

FeA =

.42

Fe< )

2.26

MnO

.OS

CaO

.32

MgO

.13

k,o

1.77

Yi.n

8.4 1

II..O

.~>7

CO,

tr.

Total 99.95

Jour. Sci., 3d ser., vol. xxxi, 18S0, p. 203.
t Mil i lie Physiographic, ii. 1887, p. 81 .

[bid . p

212

\\ . S. BAYLEY — SYENITES FROM NEW ENGLAND.

From this we calculate that the ingredients are intermingled in the
proportions shown below :

w
D

Rock.

*>— *

•

it.

I— i

Zl.

SiO

60.39

2.264

.744

7.436

17.588

32.091

60.123

.2(17

AL,(>;

22.57

1.223

.566

5.862

4.911

9.221

21.783

.787

Fe2< >3

.42 |

Fe( )

2.26 i 2.63
.08
.32

2.444
.071
.063

.067

.108

2.619
.071
.386

.014

MnO

.009

CaO

.088

.089

.146

—.06(5

MgO

.13

4.77

.043
3.818

.040
.194

.083
4.838

.047

K.,<)

.049

.004

.773

—.068

Xa,<>

8.44

.448

.388

2.825

.454

5.080

9.195

—.655

II.o

.5/

.324

.077

.146

.044

.040

.631

—.061

CO,

tr.

.124

—.124

09.95

6.886
.170 (=0)

1.991

17.042

27.014

46.920

99.853

7.056

viz: 7 per cent of lepidomelane, 2 per cent of cancrinite, 17 per cent of
eleolite, 27 per cent of orthoclase (and microcline), and 47 per cent of
all lite. As was indicated by the microscopic study, no plagioclase other
than albite is present, and this, as is seen, is largely in excess of the
orthoclase.

The rock, then, while certainly to be classed with the eleolite-syenites,
is nevertheless very unlike those that have been described from other local-
ities. It consists essentially of lepidomelane, eleolite and albite among
its undoubted primary components, and of orthoclase, albite, cancrinite
and sodalite among those of probable secondary origin. Even though
the orthoclase should he regarded as primary, it is not in sufficient quan-
tity to affect to any considerable degree the character of the rock. Its
structure is seen to be thoroughly granitic where the deformation pro-
duced by pressure is not so great as to obscure all traces of its original
character. Although, according to Rosenbusch's scheme, its composition
would carry the rook among the theralites, its characteristics certainly
point to the eleolite-syenites as its nearest relatives. The sodalite and
cancrinite of the eleolite-syenites are abundant in the Maine rock and the
dark color that is to be expected in the more basic plagioclase-eleolite
rock is lacking. The plagioclase of the former is the most acid one known.

FOUNDING OF THE ROCK VARIETY LITCHFIELDITE. 2-13

while the more basic members of this group of minerals are entirely
wanting. ( Jonsequently, in spite of the great predominance ofalbite over
orthoclase, we are quite justified in calling our rock an eleolite-syenite.
Its large percentage of albite, however, and its possession of but one bisili-
cate constituent^ and that a biotite (lepidomelane), seem to distinguish
it as a very well defined variety of eleolite-syenite, as well characterized
in the hand-specimen as in the thin section. Its peculiarities are so
strongly marked that the rock seems worthy Of a distinctive varietal
name, for which no more appropriate one can be found than litchfieldite,
derived from the familiar locality — Litchfield — whence nearly all the
specimens in the museums were obtained.

Hawks' Hornblende-Syenite from Red Hill, Moultonboro, New

Hampshire.

Historical. — The New Hampshire rock was described by Hawes as a
hornblende-syenite in these words:

"A beautiful variety comes from Red lull, in Moultonborough. It is composed
essentially of orthoclase, which exists in thin tabular twinned crystals, which
mostly lie in one plane, and consequently give to little specimens of the rock a
stratified appearance. The hornblende, which is irregularly distributed, is black,
but in thin sections it is deep yellow, and it incloses more or less biotite in its
mass. Microscopic -rains of blood-red hematite and black magnetite and crystals
of apatite are <lr ected, and by the aid of polarized light some plagioclase is found
to he present. < >nly a very Little quart/, is seen in some little angular corners made
by the melting of the straighl edges of the orthoclase crystals. Little, partially
crystallized grains of sphene are found, and some of the grains of hornblende are
shown by polarized lighl to consist of two parts in t win relationship. As there are
large accumulations of this rock, it is one of considerable importance."

Nothing is said of the method of occurrence of the rock, though similar
ones are described as existing in dikes.

Mr. .!. S. Diller, in his search for a typical syenite for the educational
series of the United Stales Geological Survey, examined specimens of
the Red hill rock sent him by Professor \V. <). Crosby, of the Massachu-
setts Institute of Technology, who obtained them in turn from a man
who was instructed to collect the material from Hawes' original ledges.
A few minute.-' survey of the specimen.-- revealed the presence of blue
sodalite, and a tiny piece treated with hydrochloric acid gelatinized
easily. Sections of the rock were then made and turned over to the
writer for investigation, the results of which are recorded in the present
article. That the material furnished by Professor Crosby represents
Hawes rock is shown by its comparison with a specimen in the National
Museum labeled in Hawes' own handwriting.

241 W. S. BAYLEY — SYENITES FROM NEW ENGLAND.

Occurrence. — As indicated in the title, the rock studied occurs at Red
hill, just north of Center harbor, in the town of Moultonboro, Carroll
county, New Hampshire. No definite information is available as to the
amount of the rock found in this place, but from published descriptions
of Red hill it seems likely that the entire eminence is composed of it ; for
we read in the "History and Description of New England ":;: that ''tower-
ing up some 2,000 feet above the level of the sea is Red hill, formed of a
beautiful syenite, in which the feldspar is of a gray-ash color."

Macroscopic Description. — So few specimens of the rock have been seen
that it will be impossible to describe the characteristics of its mass as a
whole. We shall have to content ourselves with a rapid survey of the
specimens at hand, and with a sufficiently detailed study of their thin
sections to prove conclusively that the rock is not a hornblende-syenite
as supposed by Hawes, hut is an eleolite-syenite as surmised by Diller.
The six slides examined as representing the three types of the rock thus
far obtained are. however, so nearly alike in their essential peculiarities
that they may evidently be regarded as illustrative of the principal
lent are- of the occurrence.

The specimens furnished by Professor Crosby approach nearer in
appearance to some varieties of the Arkansas eleolite-syenites than to any
rocks with which the writer is acquainted. They are moderately coarse
grained, pinkish-gray crystalline masses, containing irregular patches of
an easily cleavable, lustrous, jet black mineral that sometimes measure a
quarter of an inch in diameter and sometimes are microscopic in dimen-
sions. In the pinkish-gray portion large even surfaces of a twinned feld-
spar are easily discernible. These are cross-sections of columnar or
tabular crystals, and are the special feature- of the rock that are most
prominent. Resides these are scattered here and there dull, irregular
masses of eleolite. and occasionally tiny blue areas of sodalite. Neither
sodalite nor eleolite is so common as in the litchfieldite, while cancrinite
has not been detected in any specimens of the New Hampshire rock.

The piece in the National Museum corresponds more nearly to Hawes'
original description than do the specimens collected more recently. A
fragment of it shows a well defined banding, which is due to the flatten-
ing of the feldspars and the dark constituents and their arrangement in
planes parallel to each other. From the bending of the tlat feldspar
plates and the existence of many small fractures crossing them at right
angles to their long dimensions it would seem that the platy structure is
the result of pressure without much attendant motion. The single thin
section examined, however, affords no support to this supposition.

A third variety of the rock has recently been collected by Mr. M. M.

♦Coolidge and Mansfield: History an. I Description of New England, vol. I. 1859, p. 585.

ERRONEOUS DETERMINATION BY HAWES. 245

Smith, who has kindly furnished to the writer all the material desired.
In a letter accompanying the specimens Mr. Smith says :

"The rock I obtained on the northeastern side of Keel hill, on land belonging t<>
Mr. \Y. II. Mason. The ledge lie.- in the pasture mi the southwestern side <>f the
road."

In this variety the structure is more nearly granular than in the
case of either of the others, and the rock is much fresher. The large
twinned feldspars that are so characteristic of the first two varieties de-
scribed are lacking in this. The groundmass of the hand-specimen is of
a grayish-white color and is composed of brilliantly glistening facets of
an lintwinned feldspar and small dull gray areas of eleolite. Occasion-
ally tiny Carlsbad twins of orthoclase may lie detected, but these are rare.
In this groundmass are Large columnar crystals of a feldspar like that of
the smaller grains, and large black grains of hornblende, frequently with
idiomorphic outlines. The resemblance of this rock to a typical horn-
blende-syenite is so close that there need lie no surprise that it was called
such by so careful an observer as Hawes. The eleolite is not recognizable
in the hand-specimen until after its presence has been ascertained by
microscopical and chemical tests.

Microscopic Description and Discussion of Chemical Analyses. — A single
glance at its thin sections shows the Red hill rock to he quite different
in structure as well as in composition from the Maine eleolite-syenite.
Its components are a light-colored augite, bright green ami dark brownish-
green hornblende, brown biotite, feldspar, eleolite and sodalite as essen-
tials, and magnetite, sphene, apatite and Leucoxene as accessories. The
oldest of these are magnetite, apatite and sphene. The former is in little
irregular grains and accumulations of grains, and the sphene is in rounded
and irregular masses and in double wedge-shaped crystals, with the usual
color and pleochroism of this mineral. The apatite is present in the
familiar colorless prisms so well known. All occur as inclusions in all
the other constituents, hut they are more frequently in and around the
aggregates of the bisilicates than elsewhere.

Ne\t in age follow the iron c pounds. These, as has been stated, are

augite, hornblende and biotite, which, together with apatite, magnetite
and leucoxene, form aggregates or accumulations, the primary constitu-
ents of which separated from the magma some time before the elements
of the Light-colored groundmass in which they are imbedded.

But little of the augite remains in the rock. That which is presenl
exists as very liglil green, almost colorless core-, whose peripheries are
fringed with bright green hornblende. The maximum extinction observed
in these cores is 37°. In all cases the augite lie- imbedded In an irregular
aggregate of the green hornblende, biotite and leucoxene, -of which the

246 W. S. BAYLEY SYENITES FROM NEW ENGLAND.

first and Inst mentioned minerals are no doubt alteration products of the
augite. The bright green hornblende is strongly pleochroic in bright.
green tints in sections parallel to the vertical axis and in green and
brownish-green tints in basal sections. The cross-cleavage of hornblende
is very apparent in the latter, and sometimes this is accompanied by the
rectangular cleavage of augite. The inclusions, of this hornblende, as of
the augite from which it is derived, are apatite and small grains of mag-
netite.

Intermingled with the green hornblende and including large masses of
it are large and small plates of biotite, whose strong pleochroism is in
very dark brown and bright yellow colors. Its extinction, determined .
by means of the quartz ocular, is parallel to the cleavage, but its axial
figure opens slightly when revolved between crossed nicols. There is no
evidence that the mineral is an alteration product of augite. Its rela4
to the green hornblende and leucoxene which it inclosed declares it to .
younger than these, or, more properly speaking, than the augite froi
which these are derived. In addition to the green hornblende and the
leucoxene* the biotite also includes crystals of apatite and sphene that
are probably original separations from the magma.

Another form of the biotite is surrounded by green hornblende in such
a way that we must suppose a small quantity of the latter to have resulted
from the alteration of the former, for the borders of the mica, like those
of the augite, are fringed with a narrow rim of the hornblende.

Of the nature of the brownish-green hornblende but little has been
learned. It is frequently in idiomorphic grains, bounded by the usual
forms found on hornblende, and is often twinned according to the ordinary
law. Its color in prismatic sections is dark green, with a slight tinge of
yellow in a direction highly inclined to the cleavage, and dark brown,
ah nost < >] >aque in directions nearly parallel to it. In basal sections the ray
parallel to a is dark green, while that parallel to I) is almost completely
absorbed. The scheme for the absorption is consequently C = fc>a.
The extinction is high, certainly above 24°, and the inclusions imbedded
in the mineral are those common to the other bisilicates. Around its
edges are sometimes discoverable little masses of iron oxides that may
indicate magmatic resorption. This variety of hornblende was seen in its
greatest perfection in the slide made from Hawes' original specimen.
Here it occurs not only in the aggregated basic concretions, but also in
isolated idiomorphic grains, commonly associated with eleolite or its de-
composition products. It is also abundant in the specimens obtained by
Mr. Smith. From the fact that the mineral occurs so frequently in isolated

*The distinction here made between tin1 two titanium minerals is merely one of origin, tin'
granular secondary substance being called leucoxene, and tin- < rystallized original litanate being
dci inated sphene.

COMPONENTS OF THE SYENITE. 247

idiomorphic grains, having traces of having undergone resorption, wo
must conclude that, like the augite and the biotite, it is primary in origin
and not secondary, as is the bright green hornblende.

The colorless components forming the mass in which the dark aggre-
gates lie are sodalite, eleolite and feldspar, whose relative ages are proba-
bly in the order named. The first two mentioned are in small quantity
as compared with the feldspar, though the eleolite is in sutficient abun-
dance to characterize the rock as an eleolite-syenite. When unaltered it
is perfectly colorless. It occurs occasionally in prismatic * forms between
the feldspar, but more frequently as irregular masses associated with the
basic constituents of the rock and often surrounding them, and also as
grains included in the intergrowths of albite and orthoclase. The time
of its formation consequently was between that of the bisilicates and that
he feldspar. The inclusions in the eleolite, besides the sphene and

dicates already mentioned, are flakes of a brightly polarizing, fibrous
abstance, and tiny grains of calcite. Both of these are decomposition
products of their host, for as they increase in quantity the eleolite sur-
rounding them gradually loses its transparency and other characteristics
until finally it passes into a cloudy mass, consisting largely of a felt of
the brightly polarizing fibers, studded here and there with grains of calcite.

The sodalite is distinguishable from the fresh eleolite only in polarized
light, where it remains dark during an entire revolution. It occurs under
conditions that are exactly' similar to those under which eleolite exists.
It is found cementing the bisilicates in the basic aggregates, and is often
present as inclusions in the feldspar. Rarely is it discovered in pieces
of any size between grains of feldspar. Perhaps its most characteristic
form of occurrence is as inclusions in the feldspar. These are usually
very irregular in shape, but occasionally the grains show very clearly
the traces of dodecahedral planes (figure 2). That the isotropic grains
are sodalite and not some other regularly crystallizing mineral maybe
beautifully shown by Lemberg's test,t in which a dilute acid solution of
silver nitrate is allowed to come in contact with the uncovered section.
In a portion of a slide treated in this way the isotropic grains were covered
with :i white coating of silver chloride, while the nepheline grains re-
mained unaffected.

The sodalite, like the eleolite. is older than the feldspars, hut is younger
than the bisilicates. A single observation upon the relative ages of the
first two mentioned numerals indicate3 thai the sodalite preceded the
eleolite in the time of its format ion.

*It i- probably this that was taken by Hawes for quartz (see description, p. 243).
t J. Lembergi Zeits. d. d. geol. Gesell., b. \lii. L800, p. 738.

XXX III r.i ii, Geol, Soi . \ n., \ ol. 3. L891.

248

W. S. BAYLLY — SYENITES FROM NEW ENGLAND.

The feldspar was the latest of all the components to crystallize. It ((in-
stitutes about 80 per centof the entire rock, and occurs almost exclusively
in large Carlsbad twins, with irregular outlines. In spite of the abun-

Figuke '1. — Occurrence of Nepkeline and Sodalite in Feldspar.
l = Nepheline ; 2 = Sodalite.

dance of apparent crystals in the hand-specimen, the thin section contains
lid grains with idiomorphic forms. All have such shapes as are permitted
them hy surrounding grains; so that we have in this feldspathic portion

Figure 3. — Eleolite Syenite from Red Jli".

Tin- slide shows a portion of a basic accumulation consisting oi' biotite, hornblende, augite (rec-
i tngular cleavage), sphene (stippled), and magnetite.

of the rock an interpenetrating mass of large twinned grains, which have,

however, a well marked extension in a single direction, and thus a

COMPOSITION OF THE SYENITE.

249

columnar habit. In natural light the substance of the feldspar appears
to be homogeneous, but under crossed nicols it is seen to be an inter-
growth of two very different substances with extinctions corresponding
.to orthoclase and albite. The orthoclase has suffered the effects of altera-
tion to a much greater extent than has the albite, and inconsequence
has often entirely disappeared, while its place is now occupied by a
cli >udy aggri sgate of kaolin or of micaceous minerals. The albite remains
quite fresh, and so includes these secondary products. The other inclu-
sions of the albite. as well as those of the orthoclase, are the eleolite and
sodalite grains already referred to, with crystals of sphene, apatite, and
( lark green hornblende, and an occasional rounded grain of zircon ; besides,
of course, the usual liquid inclusions. It is not certainly known whether
other feldspars than those mentioned are present or not, but it is assured
by the analysis of the rock that if they do occur it is in but very small
quantity. A separation of the feldspar from the powdered rock by a heavy
solution points to the same conclusion ; for while a great lot of material
fell when the density of the solution was between 2.571 and 2.586, but a
trifling, quantity was precipitated on either side of these limits. AA
analysis of that portion of the powder whose specific gravity was 2. 57-2. 5s
showed it to consist partly of eleolite and partly of feldspar. These were
separated by extraction with hydrochloric acid and digestion with sodium
carbonate, and then analyzed by Mr. W. F. Hillebrand, who reports these
figures :

Si( )., .

Fe203

( !a< ) .
BaO.
MgO

K.,( ) .

X;i..< )

Nephelin,e.

45.3]
32.67

2.00

Total

.1(3
5.70
L2.60
L.56(calc.

Feldspars.

100.00

66.85

19.50

.13

.11
.07
tr.
5.80
7.11
.3]

100.21

From the rt 'sul t of this analysis il is quite plain thai the insoluble por
tion of the powder is a mixture of orthoclase and albite molecules ; and
since the microscope shows the presence of two feldspars in each grain,
it is equally certain that these molecules are in the form of intergrowths
of orthoclase and albite and not in their combination anorthoclase.

250 W. S. BAYLEY — SYENITES FROM NEW ENGLAND.

Aii analysis of the rock made by the same chemist gave:

Si02 59.01

Ti02 81

Al,,(>3 L8.18

Fe203 L.63

FeO 3.65

MnO 03

CaO 2.40

SrO tr.

BaO OS

MgO 1.05

K.,0 5.34

Na20 7.03

ZrO tr.

B2O(atl00°) 15

li.,0 (above 100°) 50

P-A tr.

CI 12

Total 99.98

A single glance at this column affirms the statement above made that
if any plagioclase other than albite is present in the rock it must be in
very small quantity, for the 2.40 per cent of CaO indicated by the analysis
is not more than enough to satisfy the demands of the 15 per cent of
augite, hornblende, biotite and sphene that are known to exist there.
Again, the percentage of K,0 is less than that of Na20. Even after allow-
ing for the excess of Xa,0 over K.,0 in the eleolite and the presence of
sodium in the sodalite, there still would remain a larger proportion of
Xa.,0 than of K.,0. This would necessarily imply that albite is in excess
over orthoclase.

Summary. — Although but few specimens of the Red hill, New Hamp-
shire, rock have been examined, enough is known of the occurrence to
enable us to declare it to be an acid eleolite-syenite, containing a larger
proportion of albite than of orthoclase. Its essential constituents in the
order of their ages are augite, hornblende, biotite, sodalite, eleolite and
the two feldspars, orthoclase and albite. Its accessory primary compo-
nents arc apatite, crystallized sphene, magnetite and occasionally zircon,
and its secondary constituents granular sphene and bright-green horn-
blende, besides fibrous decomposition products of eleolite and of ortho-
clase. It differs from litchfieldite in being less acid, in containing a little
less albite and more undoubtedly original orthoclase, and especially in the
possession of augite, hornblende and sphene, all of which are important
elements in the composition of most eleolite-syenites. Besides, the New

COMPOSITION OP THE SYENITE. 251

Hampshire rock contains original socialite, while this mineral in the
Maine rock is principally secondary. The former therefore is more
nearly a normal eleolite-syenite than is the latter, although it possesses
an abnormally high percentage of albite, as indicated by the high per-
centage of silica and the low percentage of alumina, together with an
excess of soda over potash.

Explanation <>f Plate 7.

Figure 1. — Litchfieldite in natural light. The dark mineral is lepidomelane. The
large gray areas in the lower left of the picture and the light areas
surrounded by the mica are eleolite. Everything else is albite.

.66.

Figure 2. — Litchfieldite under crossed nicols. Here the eleolite is easily distin-
guished from the plagioclase, since the former polarizes with a uni-
formly dark gray tint. Nearly all of the material included between
plates of the lepidomelane are thus seen to be this mineral. The
very light colored aggregate in figure 1 breaks up, under crossed
nicols, into a mosaic of small plagioclase grains, that surrounds the
basic elements of the rock and separates them from each other.
X .33.

(262)

BULL GEOL. SOC. AM

VOL. 3, 1891, PL. 7.

FIGURE 1 — LITCHFIELDITE , NATURAL LIGHT.

FIGURE 2 — LITCHFIELDITE ; CROSSED NICOLS.

MICROSTRUCTURF. OF LITCHFIELDITE.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 253-282, PL. 8

A REVISION AND MONOGRAPH OF THE GENUS
CHONOPHYLLUM

WILL H. SHERZER

ROCHESTER

PUBLISHED BY THE SOCIETY

May, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP. 253-282, PL. 8 MAY 24, 1892

A REVISION AND MONOGRAPH OF THE GENUS CHONO-
PHYLLUM.

BY WILL II. SHERZER.

( Read before the Society December -Jo, 1891.)

CONTEXTS.

Page

Introductory 2.">4

Historical and Descriptive 254

Type Species 257

Generic Characters 258

Growth 258

Outer Covering 259

Calyx . 259

Septa 259

Dissepiments 2(12

Central Area 262

Classification 2(>:'>

List of Species 263

Results of defective Definition 263

1 . ( 'honophyttum perfoliatum 263

2. < honophyttum elongaium 266

:;. ( 'honophyttum niagarense 266

4. ( 'honophyttum magnificum 267

5. ( 'honophyttum belli 268

6. ( nonophyttum ellipticum 269

7. Chonophyllum ponderosum 270

8. < honophyttum sedaliense 272

9. < 'honophyttum vadum 27-!

10. Chonophyllum capax 27:!

I Ascription of New Species 27 1

( 'honophyttum pseudohelianthoides 275

f 'honophyttum greenei 275

Nearest Relatives 276

< ieneral Relations 276

Omphyma 277

Ptychophyllum 278

( hjathophyllum 27'. •

Horizons and Distribution 280

XXXIV Bum Gkoi Sim \m.. Vol 3, 1891. (253)

254 W. IT. SHERZEK — THE GENTS CHONOPHYLLVM.

Introductory.

This paper will aim to do for one genus of Paleozoic corals what is
much needed for many others: it will attempt to give definiteness to the
set of characters by which the genus may be recognized, will examine
the various species assigned to it with reference to these characters, and
will indicate the special points of structure by which it may be distin-
guished from its nearest relatives.

The work was begun upon the suggestion and under the direction of
the late lamented Dr. Alexander Winchell, with the freedom of his
valuable paleontological library.

Historical and Descriptive.

In the first volume of his great work, published in 1826, the learned
( roldfuss described and figured a simple decorticated coral from Kentucky
as Cyathophyllum plicatum* The septa are stated to be somewhat thick-
ened, not converging regularly at the center, hut folded and twisted.
A few pages later, but in the same list of new species of the genus
Cyathophyllum, he described an essentially different coral from Sweden
and inadvertently assigned to it the same name. Cyathophyllum plicatum.^
Perceiving his error, the name of the latter form was subsequently
changed to C. perfoliatum on the manuscript in the museum of the
university of Bonn.'!

This Swedish coral was thus originally described :

"Top-shaped, simple and free. Thecells proliferating from the center are funnel-
shaped and thin, show a radiate regular folding instead of radial lamellae, and are
partly free at their edges, partly grown together in layers. This coral shows most
clearly the cell structure of this genus."

The excellent figure given shows the coral to differ very essentially
from Cyathophyllum as at present characterized.

In 1831 Ehrenberg presented a paper to the Berlin Akademie der
Wissenschaften, in which he refers Cyathophyllum plicatum, C. ceratites, C.
ih cuosum, C. vermiculare, C. secundum,, C. lamellosum and C. placentiforme,
all of Goldfuss, to Strombodt s of Schweigger.§ Aside from the fact that

* Petrefaeta Germanise, erster theil, 1826; page 51, tab. xv, fig. \2.

fPage 59, tab. xviii, fig. 5.

X Monographic des Polypiers Fossiles des Terrains Pala;ozoi'qui - 1851, Edwards and Haime, page
405; Histoire Naturelle des Coralliaires, Milne-Edwards, tome troisiAme, 1860, p. on.

-, Beitritge zur physiologischen Kenntniss der Oorallenthiere im allgemeinen, und besonders dea
rolhen Meeres, nebs! einem Versuche zur physiologischen Systematik derselben : Abhandlungen
der Koniglichen Akademie der Wissenschaften zu Berlin, 1832 1 1 • 1 1

FOUNDING OF THE GENUS. "255

the structure of the Kentucky form only would permit its reference to
this genus, there is no douht that this is the plicatum meant when it is
noted that the enumeration of these species by Ehrenherg follows the
order of description by < roldfuss. Had the reference been to the Swedish
coral it would have stood last in the list. Lonsdale, however, some eight
years later, in describing corals from the Wenlock limestone of England,
made this latter form synonymous with Strombodes plicatum of Ehrenberg.*
The following description and the figures which accompany it render it
almost certain that he really had in mind the structure of the Kentucky
coral, the plicatum proper and not the. perfoliatum :

"This coral is essentially distinguished from Cyathophyllum and Cystiphyllum by
internal structure, the center consisting not of transverse plates, resembling the
septa of a Nautilus, or of bladder-like cells, but of lamellae contorted spirally. In
the description of Strombodes by Schweigger and other authors, this structure is not
mentioned; it is presumed, nevertheless, that the fossil here represented is a
Strombodes, and that it is the S. plicatum of Goldfuss."

It seems very probable that figures 4b and 4c are of Ptychophyttum
patellatum, Schlotheim, sp.,f while the affinities of the other forms are
more uncertain and indeterminate from the figures and description.

In his " Silurian Fossils of Ireland " X McCoy refers certain forms,
" Rare in the green slates of Doonquin, Dingle, county Kerry," to the
Swedish coral under the name Strombodes plicatus, simply following the
lead of Lonsdale.§ Under the name Cyathophyllum plicatum, Goldf., de
Koninck described and figured a series of specimens from the Carbo-
niferous of Belgium, 1 1 comparing them Avith the original Kentucky coral
of Goldfuss in the Bonn museum. This type and the forms associated
with it have no interest in this connection further than their complete
separation from the Swedish perfoliatum.. Milne-Edwards thought that
the Kentucky coral might be referred to Hallia, E. and H.€

In a work which I have been unable to consult (the second edition of
Lamarck)** Milne-Edwards refers certain corals to the C. plicatum (per-
foliatum) of Goldfuss; and with this possible exception there seems to
have been no other specimens of this coral described or figured from
1S2G to 1850. Recognizing that this form has no relationship with
Cyathophyllum, Edwards ami Haime, in their ''British Fossil Corals."

Murchiaon's Silurian System, pt. ii, 1839, pp. 691-692, pi. 16 bis, figs. I. la, 16, 4e.
flliM. Nat. des Cor., I860, vol. iii. p. 100; Monographie der Zoantharia Scleroderma^ Rugosa
(Is;::). Wladislaw Dybowski, \>. 142.
Ink;, p. 61.
i A Monograph of the British Fossil Corals, pt. \. p. 291.
Description des AnimauxFossiles qui setrou vent dans le Terrain Carbonifere de Belgique, 1842-4,
p. -i-i, pi. e, figs. Ui-g
• in-. ,\ii. des ''"i-., vol. iii, p. ::.".;.
** Vol. ii, 1836, p. 131.

256 W. II. SHERZER — THE GENUS CHONOPHYLLUM.

founded upon it the genus Chonophyllum, and assigned to it the following
generic characters :

"Corallum simple, and constituted principally by a series of infundibuliforin
tabulae, superposed and invaginated, the surface of which presents numerous septal
radii equally developed, and extending from the center to the circumference. No
columella nor walls."*

The following year this same description reappeared in their " Poly -
piers Fossiles,"t with the additional note — " The chonophylla have some
relationship with Strombodes, but they always remain simple and present
no walls ; they differ from the ptychophylla by the absence of any cen-
tral organ.'1 This was then again published by Milne-Edwards in 1860. J
Morris, in 1854, referred the genus to the then imperfectly known Hclin-
phyllum, and this genus to Strephodes of McCoy .§ including under it the
Cyathophyllum perfoliatum of Goldfuss and the Strombodes plicatus of Lons-
dale. Pictet followed the description of the founders, simply omitting
the statement in regard to the absence of wall. II

The first American species was described by Billings in 1860,^ hut
neither in connection with this description nor with another live years
later does he offer any contribution to the generic literature. He was
guided, in all probability, by the general resemblance between his types
and the excellent figure of Goldfuss rather than by any of the generic
descriptions or his own imperfect knowledge of his specimens. Dybowski,
in his elaborate monograph on zoantharia rugosa, does not recognize the
genus. Based upon a study of the first of Billings' species, C. magnificum,
Dr. Rominger, in 1876, published the most complete and satisfactory
diagnosis of the genus yet made:**

"Single turbinate polyparia, composed of invaginated, radially plicated cell cups.
which are intimately united within the central area, and form with their linear
plications continuous vertical crests, extending through the whole length of the
corallum, and uniting in the center into a somewhat twisted fascicle, but without
composing a solid central axis. The interlamellar interstices of tins central fas-
cicle or core are traversed by transverse vesiculosa plates, but no larger transverse
diaphragmatic septa are observable. In the peripheral area the structure is en-
tirely different. The connection between the invaginated cups becomes more
loose, the linear plications open themselves and spread horizontally, forming grad-
ually widening and moderately convex hand-like folds of the expanded laminar
cup walls, which are superimposed in well-defined membraniform layers, one

♦ Brit. Foss.Cor., pt. i, 1850, p. Ixix.

j- is:, i, p. iOo.

I Hist. Nat. <les Cor., 1860, vol. iii, p. 398.

j Catalogue of British Fossils. In., i. pp. 19, 57, 64, 65.

|j Traite de Paleontologie, vol. iv, 1857, p. 457.

' Canadian Journal, new series, vol. v, 1860, pp. 264-265.

** Geological Survey of Michigan, vol. iii. pt. ii. pp. 115-116.

ROMINGER'S DIAGNOSIS OF THE (.EM'S. '1'u

reposing on the granulose prominences of the surface of another, and more inti-
mately connecting in the linear furrows between the plications, which correspond
to the interlamellar spaces of other zoantharia rugosa, but were confused by
Billings with the lamellse.

Zittel gives in liis Handbuch* a brief description of Chonophyllum
which agrees with that of Pictet. We have been unable to find any
recognition of the genus in the publications of Professor H. A. Nicholson.
Mr. S. A. Miller, in his "North American Geology and Paleontology,""}"
gives a new lease of life to the antiquated description of Edwards and
Haime.

In 1852! Professor James Hall founded his genus Conophyllum
{■•(■miiis and folium; in allusion to the inverted conical septa "), and
described the single species Conophyllum niagarense: After describing
their Chonophyllum ellipticum in 1873 Hall and Whitfield add: "This
genus is apparently identical with Chonophyllum, Hall, Paleontology <>f
New York, vol. 2, published in 1852, though actually in print more
than two years earlier.'"^ Either from this note or from the nearly
identical name, Halbs genus has been quite generally confused with that
of Edwards and Haime. The species upon which it was founded will
be shown presently to be a Cystiphyllum, so that it can in no sense be
regarded as a synonym.

( 'onfrouted with this unsatisfactory condition of the generic literature,
we begin our labors upon the genus.

Type Species.

The celebrated French paleontologists who founded the genus gave as
the type"( 'honophyllum \n rfoliatum ; < 'yathophyllum perfoliatum, < ioldf, tab.
xviii, fig. 5." This species, previously referred to, was founded upon a
single specimen from the Upper Silurian (Niagara) of the island of Got-
land. Sweden, and now deposited in the museum of Bonn university.
The figure of Goldfuss shows that the septa, instead of being lamellar
plates as in typical rugose corals, are formed by a series of superposed
layers, convex upward, and curved downward at their edges to form
the side faces of each septum. This structure is also shown, but Less
clearly, in a photograph kindly prepared forme by Professor Carl Schliiter,
of Bonn university (see plate 8, figure 1) . We regard it as one of the
chief characteristics of the genus Chonophyllum. in a letter of May 10,
1890, Dr. Gustav Lindstrom, of Stockholm, writes that in his last cata-

il i mil h del Palseontologie band i, 1880, p. 229.

I 1889, p. 177.

Paleontology of New York, vol. ii, L852, i>. ill.
; Twenty-I liird Reporl on i ii ■ State Cabinet ol New York for L8C9, 1873, p. 23U.

25S W. II. SHERZER — THE GEMS CHONOPHYLLUM.

logue of Swedish fossils he referred certain rare forms from Gotland to
this species of Goldfuss, but upon closer examination he finds them to
differ; and he considers Chonophyllum perfoliatum to be identical with
Ptychophyllum patellatum, Schloth., sp. The specimens described by Ed-
wards and Haime he regards as quite different. Owing to the confusion
thus occasioned, he thinks it would be wise to abandon the genus and
distribute its species among other genera. Professor Schluter made a
personal examination of the specimen for me and came to the same con-
clusion in regard to its relationship. He reports it taller than an ordinary
Ptychophyllum pateUalum and its septa less twisted at the center, but in
other respects similar. Reasons will be given presently for thinking that
this cannot be a Ptychoph yllum. In the meantime it seems hopeless to
try to draw any generic characters from this specimen or from any of the
early literature. If the Swedish coral and those of Edwards and Haime
were all that were to be disposed of, this paper would not have been pre-
pared. As it is, however, a well marked and interesting group of forms
occurs, readily separated from typical forms of all other genera and ap-
parently related to the original of Goldfuss. If this type coral is not
generically related to these, or if it is referable to some previously estab-
lished genus, then a new generic name must be proposed for this group.
If, however, it is so related, then it can stand only nominally as the type,
and the details of structure must be drawn from other sources. The horns
of the dilemma presented us then are(l) to alter the name of forms famil-
iar to American paleontologists for over a quarter of a century or (2) to
draw the details of structure from the second acceptable species assigned to
the genus and general characters only from the original specimen. We be-
lieve that we shall meet with the approval of most, if not all, working in
this line if we grasp the latter alternative ; and hence we have studied C.
ma.gnificum, Billings, in this way and around it have grouped the related
species. This is one of the largest and most magnificent of our simple
rugose corals, #ie first American species to be described, most widely
distributed and abundant, and showing most typically all points of
structure.

G ENERIC ( IhARACTEKS,

Growth. -The representatives of Chonophyllum must lie classed under
the monastres of Fromentel, or organisms which increase entirely by ova
rather than by gemmation or fission. In some specimens of C. ponderosum,
Rom., however, there is found a central calicinal budding of from one to
four corallites, leading to a loose variety of compound growth. The
characteristic form is short conical, turbinate or patellate, but a conico-
cylindrical growth, with little or no curving, is not uncommon in some

STRUCTURAL FEATURES OF THE GENUS. 259

species. The base may be acute or obtuse and provided with an attach-
ment sear. The outer calicinal margins are, typically, horizontally ex-
panded and at times more or less rerlexed. The size varies with the age
and species, in C. magnifiewm attaining a greater diameter than in any
other known simple coral. Fragments have been found which belonged
to specimens not less than 22 or 23 cm in diameter. The single speci-
men upon which this species was founded had a diameter of 16.5 cm
and an estimated length of 11.5 cm.

Outer Covering. — Owing to the peculiar formation of the septa there is
neither necessity nor opportunity for the formation of a true wall such as
exists in typical rugose corals. A simple, protective, epithecal covering
Avas secreted and deposited by the'"randplatte," or that portion of the
polyp projecting over the edge of the calyx. This covering conforms to
all the regularities and irregularities of the corallum itself, shows the
ordinary circular accretion ridges of growth, and is longitudinally striated
with narrow grooves and broad fiat or concave bands, gradually increae-
ing in width from the base toward the edge of the calyx. These grooves
mark the position of the interseptal cavities and the broad bands the
position of the septa themselves. Thin sections show that the epitheca
is in contact with the under concave surface of the septa only here and
there, and that it receives its support mainly from the ridges produced
by the downwardly deflected edges of the series of layers which form
them. Owing to this loose connection with the body of the corallum the
epitheca is, in many specimens, either partially or completely lost, perha ] >s
from marine or atmospheric agencies. In consequence, decorticated forms
are somewhat characteristic of the genus, and it was this fact which led
the founders to assert the absence of wall rather than any real knowledge
of the outer covering which the}7 were able to obtain from their limited
number of specimens. In all recognized species, radicinal and spinulose
processes are absent.

< 'iilj/x. — The calyx is generally spacious and deep in comparison with
the height of the corallum. In some forms, however, it may be shallow
and basin-like; in others there is an abrupt and deep central pit. with
nearly vertical sides and broadly expanded margins. The outer edges
may be horizontally explanate or reflexed upon one or all sides. The
fovea is entirely absent or it exists only in the most rudimentary condi-
tion. The bottom of the pit is in general fiat, never smooth, but in one
species (C ponderosum) a distinct elevation may be formed by the twist-
ing together of the primary septa.

Septa. — The original specimen of Goldfuss contains 76 septa; in C.
magnifiewm they range from tins number to L20 in mature specimens,,
while in C. 'ponderosum they may reach 1 I". In the specimens of Edwards

260 W. H. SHKKZEB THE GENUS CHONOPHYLLTJM.

and Haime the septa are stated to be of equal length ; but in all farms
examined we have found them alternating, of twO orders, those of the
second order terminating as they reach the central pit, those of the first
extending to the center. These primaries may remain straight or become
more or less twisted, but not so as to form a columella. Viewed from the
calyx the direction of the twist is left-handed, i. <■., contrary to the hands
of a watch.

Near the base and along the central vertical axis the septa present the
form of vertical lamella?, apparently similar to the ordinary lamellar
septa: but as they pass outward from the center and upward from the
base to the outer calyx margin they gradually thicken until in some of
the largest forms of C. magnificum they are 5 mm across at the periphery
of the calyx. In the calyx about the pit the septa appear thin and sharp,
but pass outward as gradually broadening convex hands, separated in
the outer area by very narrow grooves which mark the position of the
interseptal cavities. If the outer edges of these septa are examined in
decorticated specimens, or if vertical sections are prepared through this
outer area, each septum is seen to lie made up of a series of delicate.
regularly curved, superposed membraniform layers with their convexities
upward (figure 2). It was these spaces which Billings mistook for the
interseptal spaces * as first pointed out by Dr. Rominger.r The regularity,
distance apart, and thickness of these layers are subject to some variation
in the different species. They are most beautifully and typically devel-
oped in C magnificum, where they average about 5 or (5 to the mm, hut
range from 3 to 12 to the mm. In this same species their average thick-
ness in several thin sections was found to he about ^ mm. the thickest
being T\j and the thinnest ones observed -V mm.

Along the medial plane of each septum these layers are approximately
horizontal for a short distance, curve gradually downward toward the
sides, and finally are sharply deflected, fusing with one another along
their edges to form the side faces of the septum. Occasionally a layer, or
a series of layers, unites directly with those just beneath before reaching
the side, and thus takes no part, for some distance at least, in the actual
formation of the septal faces. When the septum has become too narrow,
an upper layer may send down its edges upon each side completely en-
wrapping as many as 12 or 15 older ones, thus suggesting their method of
growth. In general, these layers are not continuous from one septum to
its neighbor, hut each septum is made up of an independent series.
Occasionally they pass completely across for a short distance, arching up-
ward in the interseptal cavity and assisting in the formation of the vesi-

*Can. Jour., new series, vol. \. I860, p. 265.
fGeol. Siirv. of Mich., vol iii. 1S76, |>t. ii. p. 115.

CHARACTERISTICS OF THE SEPTA. 201

cles. ( Figure 2, plate 8. will lie found on minute examination to show this
structure.) These layers are drawn as continuous by Billings, not only
from septum to septum but also through the center* It is this erroneous
conception of them which has caused the genus to be described as having
complete tabulae and as made up of superposed and invaginated cell-cups.

In radial sections through the septa the cut edges of these layers appeal'
as delicate parallel lines, sloping gently from the edge of the calyx down-
ward toward the center. Intersected at right angles by the supporting
growths they present, in typical forms, a Stromatopora-like appearance
(figure 5). As the septum approaches the center the layers become more
sharply bent, the side faces are brought more closely together, and there is
formed a thin but double septum not to be distinguished from those of
ordinary corals.

As a support for these delicate layers there' are abundantly developed
upon the upper surface of each, granular or spinulose processes. In
certain specimens of C. magnificum vertical plates are formed which may
be somewhat curved or warped, presenting a vermiform appearance under
the hand lens, and arranged across the septum (figure 3). These may
be over a mm in breadth and continuous upward for several mm. actu-
ally intersecting the layers. They may start as simple spinules and
gradually widen into plates as they ascend. In certain cases they are
simply placed in corresponding, or nearly corresponding, position upon
the successive layers. These growths have their flat faces shown in figure
2, their edges in figure 5, and their cross-sections in figure 3. < >n the
side faces of the septa these growths are reduced to rounded granula-
tions, and under this form extend inward to the pit (figure 5). They
have been observed here to be at times crowded together into rows ex-
tending, for short distances, upward and outward. A rather character-
istic roughened appearance is thus given to the septa when viewed from
the calyx.

The forms which may be referred to the genus do not offer advantages
for the determination of the order of the interpolation of new septa,
owing to their general shape and structure. The widening of the septa
at the edge of the calyx endeavors to keep pace with the diametral
growth of the corallum, thus giving occasion and necessity for the intro-
duction of tew new ones. The septa generally start from the base with
an irregular spiral twist in which the foundations are early laid for
nearly all that will he needed. A young specimen of <". magnificum with
a height of 12 mm and a calyx diameter of 2-'! mm has 72 septa, while
a mature specimen of the same species. NO mm in diameter, has hut 86.
Another specimen in expanding its calyx from 18 to 100 mm and

* ('.hi. Jour , new series, vol. \ . pi. i, figs a and e,
XXXV— Bum ftnoi Stic, \m. Vol, :, 1891.

262 W. H. SHERZEB THE GENUS CHONOPHYLLVM.

growing vertically 40 mm has gained but two new septa. In some forms,
however, a greater number of new ones are introduced showing the
tetrameral structure and pinnate arrangement along the cardinal septum,
apparently following the law of Dr. Kunth. Others are introduced
irregularly, however, throughout the quadrants without regard for any
established statutes.

Dissepiments. — A well developed vesicular structure occurs in the outer,
narrow, interseptal cavities as first pointed out by Rominger. These vesi-
cles are generally delicate and rendered more or less irregular 1 >y the intro-
duction of larger ones, probably produced by the union of neighboring
septal layers (figure 4). In general they are formed by narrow bands,
united along their edges to opposite septal faces, convex upward and
superposed in such a way as to cut off the greatest amount of space with
the least expenditure of material. In this we have a clue to the use of
these structures. As the growth of the polyp demanded more commodi-
ous quarters, a gradually expanding corallum was constructed. The
lower, unoccupied portions, now entirely useless, had to be shut off from
that which was habitable by ectodermal secretions of calcium carbonate.
This was accomplished in three ways among the Paleozoic corals : (1)
by vesicles alone, (2) by tabulae alone, or (3) by a combination of vesicles
and incomplete tabula1. In the case of Chonophyllum, vesicles were
deposited in the outer area and in the central area irregular transverse
leaflets which represent rudimentary tabulae. In the case of polyps
which early matured and then continued to build a long cylindrical
corallum, as in Zaphrentis gigantea, etc. there may lie needed some such
explanation as that given by VerrilL*

In the outer area these vesicles tilled the interseptal cavities to within
one or two mm of the surface of the septa, but about the pit they were
left more open, allowing the thin septa to project with their granulated
surfaces.

Central Area. — As has previously been stated, the primary septa reach
the center as double lamellar plates, where they may be more or less
twisted, but not so as to form a columella. Vertical sections through
this region show the septa as angularly wavy, vertical lines. In the
vicinity of the pit the vesicles become more irregular and elongated,
and the plates forming them pass into irregular transverse leaflets. No
true tabula? are to be found in any of the species, although when these
leaflets occur at approximately the same level in adjoining wedge-
shaped cavities between the septa they, for short distances, may simu-
late irregular tabulae. A patch of this central area is shown in the lower
portion of figure 5 (plate 8) ; although small, it is entirely characteristic.

* Am. Jonrn. Soi., 3d series, vol. iii. 1872, i>. 187.

RELATIONS OF CHONOPHYLLUM. 2(j

( Jlassification.

■ >

Edwards and Haime located the genus in their family Oyathophyllidse,
tribe Cyathophyllinse, thus ascribing to it a regularly radiate septal appa-
ratus, superposed tabulae, and no true columella* They made no pro-
vision in their classification for a coral in which the tabulae are absent or
rudimentary, with regularly radiate septa and vesicles well developed.
In his very elaborate classification of the rugose corals Dybowski f does
not include the genus, and no satisfactory disposition can be made of it
either in his scheme or in the much simplified form of it adopted by
Zittel. This latter author places the genus under Diaphragmatophora,
Dyh., thus ascribing to it complete tabulae with dissepiments wanting
or rudimentary. 'j

The characters to he taken note of in its classification are a tetrameral,
simple growth; regularly radiate septa formed by delicate, superposed
layers, convex upward; a simple epithecal wall; well developed dis-
sepiments; and absence of fovea, columella, and true tabula?. These
peculiarities of structure require that special provision he made for the
genus in any classification adopted.

List of Species.

- Results of defective Definition. — When we consider the vagueness which
has characterized the genus Chonophyllum we are not surprised to find
a wide range of structure in the species assigned to it. Tabulae well
developed, tabulae absent ; dissepiments occupying hut a portion of the
corallum, dissepiments filling the entire visceral cavity; septa remark-
ably developed ; septa reduced to mere ridges or rows of spines. In the
ten species thus far assigned to the genus there are at least five different
genera represented, and of those who have described them, excepting
possibly those who have worked conjointly upon a species, no two have
had in mind the same set of generic characters. As the result of some
correspondence with those who have worked furthest in this line, I have
found them generally loth to express any opinion in regard to the
distinguishing characteristics of the genus.

1. Chonophyllum perfoliatiini, Goldfuss, sp.

Cyathophylium plicatuvi, Goldf. Petref. Germ., erster theil, L826, p. 59,

tah. xviiij fig. 5.
Cyathophylium perfoliatuvi, Goldf. MSS. in Bonn museum.

!'■! n Foss. ' lor., 1850, |,i. i, p. Ixix.
t Mon. der Zoan. Scler. Bug., 1873, pp. 74-84,
Hundb. der Pal., vol. i, 1880, p, 229.

264 W. II. SHERZER — THE GENUS CHONOPHYLLVM.

Cyatkophylluin plicatum, Milne-Edwards. Sec. ed. of Lamarek, t. ii, 1836,

p. 481.

Ckonophyllum perfoliatum, Edwards and Haime. Pol. Foss. des Terr. Pal.,

1851, pp. 405-'6.
" " Edwards and Haime. Brit. Foss. Cor., pt. iv.

1853, p. 235, tab. 1. fig. 5.
" •• Milne-Edwards. Hist. Nat. des Cor., vol. iii.

18(50, p. 399.

The original description of this species has been quoted, and the opin-
ions of Dr. Schliiter and Dr. Lindstrom have been cited. The Swedish
coral has a turbinate growth, but is elongated by successive expansions
and contractions of the calicinal margins. It has the central pit and
horizontally expanded growth found in many forms of Ckonophyllum
(figure 1). No fovea is indicated. There are 76 septa, but slightly twisted
at the center and showing in the photograph, under a magnifier, a coarse
granular appearance. Each septum seems to he made up of curved, super-
posed layers just as in the forms described, although they are flatter than
in C. magnificum. They are regularly convex upward and not angular.
The general shape of the corallum, with the central pit and explanate
margins, the absence of fovea, the slight twisting of the septa at the
center, their granular appearance and their formation of convex, super-
posed layers — all taken together, render it more than probable that this
coral is generically related to our C. magnificum. Goldfuss has certainly
figured for us a Ckonophyllum, whatever may he the true position of the
coral itself.

There is nothing about the descriptions of this species by Edwards
and Haime in any way suggestive of the structure assigned to it by
Goldfuss — '"a regular, radiate folding instead of radial Lamellae." Their
descriptions would apply equally well to many species of very different
genera. That given in their '; British Fossil Corals " reads as follows :

"Corallum simple, straight, rather elongate. Calice nut remarkably deep, and of
a subcorneal form. Septa (60 to 74) equally developed, straight, and extending
almost to the center of the corallum. Some vestiges of a rudimentary septal fos-
sula are visible. Height about •'! inches, diameter about 2 inches. Found at Tor-
quay. (Collection of Dr. Battersby.) A fossil found at Wenlock, and belonging to
the collection of M. d'Archiac, appears to belong also to this species."

For any information concerning the actual structure of these forms we
must rely upon the figure.* The specimen figured is imbedded in a mass
of foreign material ami shows an irregular longitudinal section near the
center. It is about 8 cm in length by 5 cm in breadth, in general form

*Lor. cit., tab. I. fig. :..

IDENTIFICATION OF EDWARDS AND HAIME's FIGURE. 265

and shape of the calyx similar to the Swedish coral. The corallum is
represented as made up of approximately parallel and wavy horizontal
lamina', averaging about two to the mm. These were supposed to repre-
sent the complete tabulae. We know of nO coral outside of the genus
Chonophyllum proper which could present a longitudinal section similar
to that shown in the lower two-thirds of this figure. We have prepared
a corresponding section of C. ponderosum which is strikingly similar in
general appearance. In this portion of the figure these layers are not
continuous through the center as they appear in the upper third, but
here are drawn the vertical edges of the central septa, under a lens show-
ing the angularly wavy appearance described for C. magnificum. Support-
ing growths are represented throughout the section. We regard this
specimen as belonging to the genus, probably to the same species as the
Swedish coral, and cut so as to show the edges of the septal layers. The
upper portion of the figure, however, it must be confessed, with these
layers continuous across the central cavity, could not have been copied
from a Chonophyllum. it may be to some extent ideal, as are the two
figures of Billings previously referred to.

A later reference is made to the Wenlock specimen mentioned above : *

"It is nut without some hesitation that we referto this species, already described
in the preceding chapter as being common in the Devonian formation, a coral found
by M. d'Archiac in .the Silurian rocks at Wenlock. The only apparent difference
between this fossil and the Torquay specimen consists in the form of the calice, the
border of which is not everted."

This specimen as figured t has a length and diameter of about 4 cm.,
is obtusely pointed and slightly curved. The calyx is basin-shaped
without explanate margins, and shows no fovea. There is a well devel-
oped epitheca, giving here and there the appearance of coarse radiciform
processes. The septa number about lot), and are apparently angular.
The general form of the coral and its calyx, the well developed epitheca
and radiciform processes, combined with the apparently angular or" roof-
shaped " septa, convinces us that this is an Omphyma, found abundantly
in the same locality, in which the fovea' are obsolete, as frequently happens.

A specimen figured by Pictet as belonging to this species is slenderly
cylindrical, the surface giving the appearance of invaginated, projecting
cell-cups.;}; Its structure may conform to the description of Edwards and
Ilaiine. hut it has no affinity with Chonophyllum.

A coral which is supposed to belong to this species was collected from
tie' Devonian of the Eifel by Dr. I {on linger, and is now deposited in the

* Loc. Hi., pi. v. p. 291.

i l."<\ ' ii tab. lxviii, figs. - and 2a.

\il i- i., ■ Ti Hi'' a.' PalGontologie, ' pi 108, tin. 2.

266 W. H. SHEKZER — THE CENTJS CHONOPHYLLUM.

museum of the university of Michigan. It has a height of 10 cm and a
diameter at the broadest part of 7 cm. In its general structure and ex-
terna] appearance it suggests the specimen of Edwards and Haime. On
closer study, however, it is found to possess all the essential characters of
Cyathophyllum helianthoides, Goldf., some abnormal growths of which are
figured from the same locality by Goldfuss.* The septa are lamellar, and
are angular or " roof-shaped " in the outer area, polished sections show-
ing the structure to be afterward described as peculiar to this form.
Several buds have started in the outer area which show the character-
istic reflexed growth and the compound tendency of the coral.

2. Chonophyllum elongatum, Edwards and Haime.

Chonophyllum elongatum, Edwards and Haime. Pol. Foss. des Terr. Pal.,

1851, p. 406, pi. viii, tigs. 1, la.
" " Milne-Edwards. Hist. Nat. des Cor., vol. iii,

i860, p. 399.

Under this name Edwards and Haime described a second species in
1851 as follows :

"Conallum elongated, cylindro-turbinate, straight or very feebly curved, present-
ing a great number of projecting swellings and interruptions in the continuity.
Epitheca well developed ; the exterior portions of the corallum sub vesicular. Calyx
moderately deep. 74 to 76 septa, very slender and equal. Height 7 to 8 cm; diam-
eter of calyx, 2to3. Devonian, Fiance ; Nehou (Manche). Collection of Verneuil."

Their figure 1 shows a slender, cylindrical coral, apparently made up of
a series of invaginated cell-cups, the irregularities of which give exteriorly
a sul (vesicular, roughened appearance, la is a view of an enlarged
calyx, showing the septa angular in the outer area, as is seen in Omphyma
and Ptychophyllum. The general shape and structure of this specimen
and the thin angular septa certainly remove it from the forms which we
have grouped about C. magnificum. It was stated by the founders to
differ from C. perfoliatum by its more elongated, slender form and more
infundibuliform tabulse.f

3. Chonophyllwn iiiagarense, Hall, sp.

Conophyllum niagarense, Hall. Pal. of X. Y., vol. ii. 1852, pi. xxxii. ftgs.

4 (i-ii.

Cystiphyllum ni<t</<tr<iiis<\ Rominger. (ieol. Surv. of Mich., vol. iii, pt. ii,

1876, p. 138, pi. xlix, fig. 3.

* Loc. ''it., tali. xx.

fBrit. Foss. Cor., pt. iv, ]> 235.

RELATIONS OF CHONOPHYLLUM. 267

The genus Conophyllum was founded upon a group of corals from the
lower Niagara of New York, described by Professor Hall as Conophyllum
niagarense. For reasons already pointed out, these have been quite gen-
erally included under Chonophyllum, and Mr. S. A. Miller figures a speci-
men as illustrative of this genus.* Alter examining a series of specimens
from New York, Michigan, Indiana, Kentucky and Iowa, we have no hesi-
tancy in assigning them to Cystiphyllum, although the septa are at times
more than ordinarily well developed. The specific description and the
figures given by Hall leave no doubt as to the position of these forms :

"Irregularly cylindrical, elongated or subturbinate, more or less expanding
above, externally rugose at intervals (when weathered often very rough) ; cup
regularly concave, deep; lamella' thin, distance from each other equal to their
thickness, denticulated on their upper and inner edges ; transverse dissepiments
corresponding to the concavity, and forming the cell or cup, and extending upwards
to the margin.

"In this fossil, the rays become in fact subordinate to the dissepiments; and the
character would be more correctly denned, by describing the coral to consist of a
series of concave discs or inverted cones setting one within the other, having their
upper surface marked by radiating rows of denticles. The form is very irregular,
varying from small, short, turbinate forms to elongated cylindrical ones in which
the diameter scarcely varies throughout. The weathered surfaces present the
arrangement of the dissepiments more or less perfectly in numerous specimens. I n
one or two instances, I have seen specimens where the weathering developed the
rays more prominently than the dissepiments, and in such instances the surface is
beautifully denticulated."

4. Chonophyllum 'nuignijinmi, Billings.

Chonophyllum magnificum, Billings. Can. Jour., new ser., vol. v, 1860, pp.

264-265, pi. i.
Rominger. Geol. Sur. of Mich., vol. iii, pt. ii,

1876, p. 116, pi. xliii.
Davis. Kentucky Fossil Corals, pt. ii, 1885, pi.

101. tig. 3; pi. 103, figs. 12, 13. 14.

This species, to which frequent reference has been made, was founded
by Billings in 1860 upon a specimen imbedded in a mass of Devonian
Limestone, Walpole township. Canada West. He was entirely misled by
the very peculiar septal formation, supposing the broad septa to represent
the interseptal cavities, and the narrow grooves of the calyx to mark" the
position of the septa. His description reads as follows:

" Short, turbinate, expanding to the width of six or seven inches at a height of four
inches and a half; upper surface constituting a nearly Hat circular disc, with a
rounded cavity in the middle, one inch and a half wide, from winch radiate one

+ X. \. Geol and Pal., 1889, p. 177.

268 W. H. SHERZER — THE GENUS CHONOPHTLLVM.

hundred and twenty-five depressed convex ridges ; the grooves between them nar-,
row ami somewhat angular in the bottom. These ridges are gently curved in cross-
ing the broad flat margin of the cup. The depth of the central cavity is about
one inch. A transverse or horizontal section shews that many of the septa (prob-
ably one-half of them) reach the center. In a vertical section, extending down-
wards, so as to cutoff the outer extremities of a few of the radiating ridges, it is
shewn that the grooves on the floor of the cup indicate the position of the septa,
and that the ridges are the interseptal spaces. The structure, as exhibited in this
section, consists of excessively thin, parallel, horizontal laniinse (apparently from
thirty to forty in the thickness of one line). These laminae are arched upwards be-
tween the septa, the curve corresponding with the convexity of the radiating
ridges. In the lower part of the corallite, the interseptal tissue is much coarser.
The surfaces of the radiating ridges appear to he covered with small tubercles."

The growth of this species varies from short, broadly explanate forms
to those conico-cylindrical in shape. In the latter the calyx diameter is
seldom over (> or 7 cm, while in the former it may reach a breadth of 22
or 23 cm. There is typically a central pit and broadly expanded calici-
nal margins : no fovea. The septa are alternating in length and vary in
number from 75 or 80 to 125 in adult forms. The epithecal covering,
structure of the septa, the dissepiments and central structure have been
already described in detail under the general description of the genus.
Billings states that "this species resembles ChonophyUum perfolialum
(Goldfuss), but is much larger, and has double the number of radiating
septa." Although in general not possessing double the number of septa, it
has more septa and is a larger form. The septal layers are more delicate.
regular and more strongly curved. Besides being found in ( 'anada 'West,
it has also been collected from the Upper Helderberg linn-stone- of
Mackinac island: falls of the Ohio ; Charleston landing; Indiana, and
it is occasionally met with in the drift.

5. ChonophyUum belli, Billings.

ChonophyUum belli, Billings. Can. Nat. and Geol., new ser., vol. ii. 1865,

pp. 431-432.

The types of this second species of Billings are deposited in the museum
of the Canadian geological survey, Ottawa, and bear the label Ptycho-
phyllum belli, in his own handwriting. They were assigned, however, to
ChonophyUum and described as follows:

" Sub-turbinate, enlarging from a pointed base to a diameter of eighteen lines in
about two inches, then becoming more cylindrical. Length, three or four inches :
greatest diameter observed, at the cup. thirty lines. Cup, in the largest specimen
seen eight lines wide and six lines deep with slightly sloping walls, apparently
flat in the hot tom with the exception of a rough styliform projection in the center ;
edge of the cup narrowly rounded, a broad flat or gently convex margin all round

IDENTIFICATION OF BILLINGS' TYPE. 209

which is nearly horizontal or slightly sloping outwards and downwards. In the
inside of the cup there are ahout seventy thin, sharp, slightly elevated septa, alter-
nately larger and smaller. These, in radiating outward across the broad, flat
margin to the periphery, are gradually changed into rounded ribs, some of them
half a line wide. The body of the fossil, as shown in several weathered and silicified
specimens, is composed of numerous irregular infundibuliform layers which are, in
some places, in contact, and elsewhere, separated, sometimes three lines apart. Sur-
face, unknown. This species shows that Chonophyllum and Pty'chophyllum are closely
related genera." Manitoulin island, Clinton formation, Canada West.

Through the courtesy of Mr. J. F. Whiteaves, of the Canadian survey,
we have had an opportunity of examining one of the best preserved type
specimens of this species. The above description is of a Ptychophyllum
rather than a Chonophyllum, and to this genus we were disposed to refer
these forms. However, upon an examination of this type, we find no
reason for removing it from the genus to which it was referred by Billings.
The turbinate form, the central pit in the calyx, the broadly explanate
margins traversed by the widening, convex septal ridges, are all sugges-
tive of the genus. These septa do not become angular in the outer area
and show no more twisting at the center than may be found in accepted
species of Chonophyllum. The specimen is silicified in such way as to
conceal the actual structure of the septa, but where it is indicated it seems
1 1 > agree; with that already described rather than with that of Ptychophyllum .
Until more can be known of the internal structure of these corals they
with propriety may be retained in the genus. It is a smaller form than
('. magnificum, with fewer septa. The septal layers are coarser and less
strongly bent and the supporting growths are not so well developed, if
present at all. Knowing so little of the internal structure of this species
and of C. perfoliatum, it is difficult to point out any definite characters by
which they may be separated. The septa in the latter are but little
twisted at the center, but this character is variable in the same specie-.

6. Chonophyllum ellipticum, Hall and Whitfield.

Chonophyllum (Ptychophyllum) ellipticum, Hall and Whitfield. 23d Rep. of
N. Y. Stale Cabinet for 1869, 1873, p. 233, pi. (.», fig. 13.

"Coral sin ill, subturbinate, laterally compressed, and much distorted in growth ;
rays somewhai strongly developed and numerous, very slightly twisted as they-
approach the center of the cup. Calyx shallow, with rapidly ascending sides in
young specimens, ami spreading nearly horizontally toward the margin in older
forms. Exterior of the body covered by a continuous epithecal coating, increasing
in strength from In 'low upward. In a vertical section the infundibuliform cups are
somewhal distant, broad al the base, with rapidly ascending sides; thespaces be-
tween them, air I a Ism between t h- rays, are filled with numerous, irregular, cystos ■
partitions.

\\\ VI I'.i ii i, im Soi \n V.. i :. 1891

270 \V. II. SIIERZER — THE GENUS CHONOPHYLLUM.

"The distinctive features of this species consist in its elliptical outline and dis-
tinctively marked rays. There may be some doubt as to its generic relations-
The rays are very slightly twisted as they approach the center of the cup, hut
there is no appearance of a columella. The great development of the rays, and
the continuous epithecal coating, arc features which pertain more particularly to
Ptychophyllum than to Chonophyllum.

"For, until), i ami locality : In the marly beds at Rockford, Iowa.''

An examination of s] >ecimens from the same localhVy (Hamilton group)
shows lamellar septa, well-developed horizontal tabula? through nearly
one-half the visceral cavity, and in the outer area a very coarse vesicular
structure. After describing his Cyathophyllum houghtoni from the Hamil-
ton group of Michigan, Dr. Rominger adds:*

"A coral described by Hall under the name of Chonophyllum ellipticum, from the
Hamilton group of Iowa, agrees in structure with the described form, but not with
< Tionophyllum."

The specimen figured on plate xxxvi, upper tier, center, shows a struct-
ure very similar to that seen in vertical sections of Chonophyllum ellipticum.

7. Chonophyllum ponderosum, Rominger.

Chonophyllum ponderosum, Rominger. Geol. Sur. of Midi., vol. iii, pt. ii,

1870. p. 117, pi. xliii.

This peculiar coral, in regard to the generic relations of which there is
no doubt, is from the lower Devonian strata of Michigan. It was thus
originally described :

" Patellate, depressed, conical polyparia of irregular, unsymmetrical, clumsy
growth, with gemmation from the center of the calyces, of single new cells, or, in
rare instances, of from two to four confluent or imperfectly defined calyces. End
cells shallow, explanate at the margins, more abruptly depressed in the center,
which is surrounded by a cycle of low linear crests uniting in it with twisted ends.
Expanded marginal part radiated by flat, broad, band-like plications of papillose
surface. The specimens are all formed of a heavy, compact mass of amorphous,
white, ivory -like carbonate of lime, or partially silicified, and with scarcely a trace
of the organic structure preserved ; only in a few specimens could enough of it be
seen by which to recognize the generic relations of the specimens and their corre-
spondence with Chonophyllum.

" It does not seem to be the mode of petrifaction which obscures the structure, as
we rind this coral in many different localities associated with other corals exhibit-
ing the finest details of structure, while they everywhere present the same massive,
compact condition. The coral appears to have, during the progress of its growth,
tilled out all its cellulose cavities as soon as the fleshy parts of the animal aban-
doned them.

" It occurs rarely in the Upper Helderberg limestone, but is abundant in certain
layers of the Hamilton group of Thunder hay, and is also found in Little Traverse
bay."

i ■■ ol. Sur. of Mich., vol. iii. pt. ii, p 105

ORIGIN OF CARBONATE IN CORALS. 271

We have collected a scries of specimens from the locality producing
the types (Phelp's quarry, Alpena, Michigan), and from these have been
al )le to learn something further in regard to the internal structure. The
septa are made up of superposed layers, convex upward, as in C. mag-
nificum, but they are coarser and more distant in proportion to the size
of each septum. They are also flatter, being less deflected at their edges.
In specimens in which they could be satisfactorily counted they average
from 15 to 20 to the cm and occupy a corresponding position in neigh-
boring septa as though deposited simultaneously. The supporting
growths are present, rising vertically through a series of the septal layers.
The interseptal cavities are narrower and less distinctly defined than in
type forms. We were unable to find a radial section clear enough to
show defined vesicles in the outer area, but toward the center they come
into view as the transverse leaflets between the contorted septa, taking
the place of true tabulae.

There are several considerations which lead to the conclusion that the
solid deposits of carbonate' could not have been made by the polyps
themselves :

1. Some of the associated fossils are filled in just as completely with
material indistinguishable from that of C. ponderosum. The best example
is that of Strombodes alpenensis, Rom. Numerous corals and crinoid
stems were collected, showing a similar structure but in which the de-
posit was less compact and hence softer. A colony of Acervularia with
a height and diameter of about ten feet showed patches and layers of
this material nearly or quite obscuring the structure.

2. That these deposits did not take place directly in the inhabited
calyx is evidenced by the layered structure and supporting growths.
From the lower abandoned portions of the corallum the polyp was, in
the main, completely shut off by septal layers and dissepimental struct-
ures.

3. The process would have been uneconomical and highly wasteful of
building material. So far as we can see, it would have been of no special
value to the polyp. Solid deposits may be found in some modern,
delicately branching corals, evidently for the purpose of strengthening
them, but no such use could be assigned in the case of a simple, turbi-
nate form.

4. Spherulites, corresponding in appearance and structure with '"'or-
bicular silica,1' were found imbedded in this solid deposit of a specimen.
They were numerous about the calyx, and on eating away the under side
of the specimen with acid they were revealed in still greater numbers,
along with crystals of iron pyrites. Each spherule consists of a rounded
lindens of silica, whitish and opaque to the eve, but crystalline in struct-

272 VV. II. SHERZER — THE GENUS CHONOPHYLLUM.

ure, surrounded by successive routings of the carbonate. The silica must
have been deposited from infiltrating water 'previous to the deposition of
the calcium carbonate.

5. Thin sections, under polarized light, show a uniform mass of fine,
interweaving crystals, many of which have their axes turned in the same
direction, so that upon revolving the microscope stage the field extin-
guishes in large irregular patches. Sections of Strombodes alpt -m nsis are
identical in appearance, while those from the Acervularia above mentioned
differ only by being more coarsely crystalline.

6. Portions of specimens, especially through the center, have been
t'i >und from which the deposit is absent. It is not improbable that diligent
search may bring out specimens from which it is entirely so.

This species is separated from all others by its more irregular growth,
by more numerous septa, which are decidedly twisted at the center, and
by the solid deposits of calcium carbonate.

8. Chonophyllum sedaliense, White.

Chonophyllum sedaliense, White. Cont. to Paleontology* 1880, Nos. 2-8,

]>. 157. pi. 39, fig. la.

The original description of this species reads thus :

"Corallum moderately large, approximately straight, the angle of divergence of
its Bides being quite small; calyx apparently rather shallow; rays numerous; sur-
face rough by the presence of numerous projecting successive calyx-borders, and by
coarse, irregular longitudinal strige. Only one example has been obtained, and thai
lias been broken off at the lower end, and also somewhat crushed. Its full length
was probably about 130 millimeters, and the diameter of the calyx about 30 milli-
meters.

"Position and locality. Near the top of the Chouteau limestone (Kinderhook
division of the Subcarboniferous series), Sedalia, Mo., where is was obtained by
Professor G. C. Broadhead."

The figure given bears some general resemblance to that of Chonophyllum
elongatum, E. and H.

Some half dozen specimens of this form, kindly sent by Professor
Broadhead, are now before me. They have a conico-cylindrical growth.
strongly curved near the base, and are all more or less compressed. The
specimen in which the structures are best preserved had an exceptionally
long cylindrical growth, this fragment being 14.5 cm in length and as
broad at one end as at the other (3.5 to 4 cm). A polished cross-section
shows 17<» very thin, alternating septa, the primaries reaching the center,

* Extracted from the 12th Ann nil Reporl ol the U.S. Geol. and Geog. Survey of tin- Territories for
the year 1878.

NON-IDENTIFICATION OF WHITE'S SPECIES. 2

_ i •>

while the secondaries do not extend more than one-third of this distance
and being, at their inner edges, curved toward the primaries, at times
apparently uniting with them. The fovea is indicated upon one side in
this section by a dwarfed primary septum and a very decided pinnate
arrangement of the neighboring ones, such as occurs in Aulacophyllum,
E. and H. Between the septa are seen the cut edges of the dissepiments,
most abundant in the outer area, gradually diminishing toward the center.
A more complete study of the internal structure will he made before
locating this species, hut sufficient has been pointed out here to show
that it is not the Chonophyllum which we have attempted to characterize.

9. Chonophyllum vadum, Hall.

Chonophyllwm vadum, Hall. Corals of the Niag. and Up. Held. Groups*

1882, p. 6.
Hall. Geol. of Ind., 12th Rep., 1882, p. 272, pi. 15,
figs. 1-4.

This species was thus originally characterized by Professor Hall :

"Corallum simple, turbinate, straight or slightly curved, acute at the base, regu-
larly expanding to tbe calix ; exterior with numerous abrupt constrictions, and
fine concentric striae ; external cost« very distinct ; height 35 mm ; diameter of
calix 20 mm; depth ID mm; sides slightly concave ; a fiat space at the bottom 5
mm in diameter; number of lamella' 70, flat, and of nearly uniform size at the
margin, becoming thinner and alternating in size below ; the principal ones extend-
ing to the center, where they are twisted and very slightly elevated.

" Formation "//</ locality. — Niagara group, Louisville, Kentucky."

We have seen no authentic specimen of this species, and this descrip-
tion, based simply upon external characters, is far from being so satis-
factory as we could desire. With the exception of the " flat " septa in
the outer area, there is nothing about it to suggest the genus Chonophyl-
lum. The general form of the specimens figured and the thin angular
septa in figure 3 seem sufficient for their rejection from this genus.

K>. Chonophyllum capax, Hall.

Chonophyllum capax, Hall. 35th hep. X. V. State Mns. for 1881,1884,

pp. H(M 1.

Although not accompanied by any figures, the description of this
species is more complete, and it can more positively be asserted not to he
a Chonophyllum,.

♦ Advi -I ts from the Thirty-fifth Rep. of the N, Y State Mus For 1881, 1884, p ii".

274 W. H. SHERZER — THE GENUS CHONOPHYLLVM.

" ( 'o rail mil simple, broadly turbinate, regularly expanding; exterior with numer-
ous concentric wrinkles and striatums. Externally there are numerous slender
processes, quite evenly distributed, which served for attachment and support ;
when exfoliated the exterior has a somewhat compressed vesiculose appearance;
corallum consisting of thin, superimposed laminae; height 35 mm; diameter of
calix 60 mm; depth 12 mm; for a distance of 20 mm from the margin it is
gently sloping, then nearly vertical ; a convex space at the bottom 15 mm in diam-
eter; tabulse thin; fossette small, deep, not extending on the side of the calix-
number of lamellae 160, alternating in size, the smaller ones rudimentary, not more
than one-sixth the thickness of the others; near the margin the larger ones are
broad, angular, having a width of about 1.50 mm becoming thinner as they ap-
proach the center where they are twisted and elevated, forming a false columella.

" This species has nearly the same form as P. [Ptychophyllum"] fulcratum ; it has also
similar processes for attachment, and might, on a cursory examination, be mistaken
for that species, but it is much more distinctly composed of thin, invaginated
lamina'; the lamellae are decidedly alternating in size and there are well devel-
oped tabulae.

"Formation and locality. Niagara limestone, Louisville, Kentucky."

The deep fovea, angular septa, well developed tabulae, invaginated
laminae, false columella, and radiciform processes leave no doubt but
that we have here a genuine Ptychophyllum.

In the plates of Kentucky corals * for which no text has yet been
issued, Mr. Davis figures two supposedly new species of Chonophyllum
from the Devonian and assigns the specific names, nanum and multipli-
cation. The photographs reveal no structure in either which can bring
them into this genus.

From this list of species we have found C. perfoliatum, C. magnificum,
C. ponderosum and possibly C. belli, which possess structures sufficiently
closely related to permit of their being grouped under one genus.

Description of New Species.

(Plate 8, figure 6.)

We have made a study of two forms, not previously described, which
are most properly referred to this group, and we append descriptions.
The first is of a specimen collected from the Upper Silurian of Conje-
pruss, Bohemia, by Dr. Rominger, and described here with his permis-
sion. The name pseudohelianthoides is of his suggestion. The second
species is founded upon a specimen from Louisville, Kentucky, collected
by Mr. G. K. Greene, in whose honor it is named.

*A Monograph of the Fossil Corals of the Silurian and Devonian Rocks of Kentucky, pt. ii, 1885,
pi 78, fig. 6, and pi. 80, figs. 11, 12 and 13.

FOUNDING OF NEW SPECIKS. 275

Chonophylhom pseudohelianthoides, n. sp.
(Plate 8, figure 6.)

Simple, short conical in growth, with a central pit in the calyx, 1:5 cm
in diameter and 5 mm in depth. The side walls of this pit curve up-
ward and outward, and the outer margins are regularly reflexed as in
Cyathophyllum helianthoides, Goldf. The bottom of the calyx is flat for a
distance of 7 or 8 mm and shows no fovea. The length of the specimen
was about 2.5 cm, and the expanded calicinal margins reached a breadth
of 5 cm. Only traces of the outer epithecal covering remain. There are
72 alternating septa, the secondaries terminating at the outer edge of the
pit, while the primaries reach the center without any twisting. They arc
thin in the vicinity of the pit, but gradually widen into low granulose,
convex hands, 1.5 to 2 mm in breadth, leaving very narrow grooves in
the outer reflexed portion of the calyx. These septa are formed by
radial curved plates superposed as in other species of the genus, but less
regular in form and position. They average about 30 to the cm. Radial
sections through the septa give a vesicular structure instead of the parallel
edges seen in (1 magnificum and 0. ponderosum. The septal layers are
here shown to be quite irregular and anastomosing so as to form elongated,
narrow vesicles. The interseptal cavities are not so well defined as in
typical forms of the genus, the septal layers passing into them, abutting
against one another, and in places interweaving. The vesicles are rela-
tively coarse and irregular toward the center, passing into the typical
transverse leaflets and not forming tabula?.

Formation and locality: Upper Silurian, Conjepruss, Bohemia.

This species is distinguished from previously described forms by its
very regular, reflexed growth and the irregularities in its septal structure.

Qhonophyllum greenei, n. sp.

(Plate 8, figure 7.)

Simple, of conico-cylindrical growth, having an original length of
aboul 5.5 cm and a calyx diameter of 3 cm. The base has been lost.
and but a faint indication remains of the outer covering. The succes-
sive calyces in the lower half of the corallum are oblique to the axis, as
though it had been compelled to grow away from an obstruction. The
calyx has a centra] pit, 1.5 cm in diameter and 1 cm deep, with a
roughened horizontal bottom, slightly depressed around the outer edge,
hut showing no fovea. The side walls of the pit are nearly vertical, and
at the tup roundoff into a horizontal ring-like expansion aboul 1 cm
broad. The septa, number ~'l and are of two orders, the secondaries
terminating at the outer wall of the pit. while the primaries reach the

276 W. jr. SHERZER — THE GENUS CKONOPHYLLUM.

center without any decided twisting. They are roughly granulose on
the upper surfaces, sharp in and about the pit, hut toward the outer area
becoming broad and convex, attaining a width of 1.5 mm and leaving
narrow interseptal grooves. These septa are formed of curved layers,
convex upward, which are typically deflected downward at their edges
to form the side face-, but which frequently pass into the poorly defined
interseptal cavities and abut against those of adjoining septa. Com-
pared with C. magnificwn, they are coarser and more distant in propor-
tion to the size of the septum and less strongly curved. Apparently in
corresponding position, they give an appearance of invaginated cell-
cups to the corallum. Vertical tangential sections show at times a central
radial supporting plate, extending upward through a number of layers,
very suggestive of that to be described for Oyathophyllum helianthoides.
These plates may be double, branching and irregular. Radial sections
through the septa show the edges of these layers curving upward and
outward, intersected by the supporting growths, and forming elongated,
flat vesicles somewhat as in the preceding species. Between these
septal plates more delicate vesicles are interposed, so that in grinding
down such sections it is not easy to tell where the interseptal cavity
ends and the septum begins.

The central part of the corallum has been dissolved and only the
outer silicified portion remains, so that the central structure cannot be
studied so thoroughly as desired. The vesicles are well developed, a<
shown in radial sections through the interseptal cavities and in vertical
tangential sections uniting the septa. They are irregular in size and
arranged in curved rows inclining upward and outward. In grind-
ing the specimen down and examining it at the successive stages, it was
found that no well defined tabulae are present. Transverse leaflets, con-
cave upward or flat, are placed in the wedge-shaped interseptal cavities,
and rather closely approximated. When placed ;it approximately the
same height in neighboring cavities they simulate irregular tabulae for
short distances.

Formation and locality: Niagara limestone, Beargrass creek, near
Louisville, Kentucky.

Tins species is less turbinate and expanded than other forms of Chono-
phyllum. Its shape is more suggestive of the larger, conico-eylindrical
forms of C. magnificum. It is readily distinguished from the3e by the
irregularities in the septal structure, the layers being coarser, more dis-
tant and less curved. f

Nearest Relatives.

General Relations. — The separation of this genus from those closely
related to it. and most liable to be mistaken for it. becomes a matter of

TAXONOMIC RELATIONS OF CHONOPHYLLUM. 277

some importance. It has been confused more with Omphyma and Ptycho-
phyllum than with any other genera; more, however, from external
resemblance than from actual similarity in details of structure. We
present here the essential characters of these genera and the points by
which typical forms of each may be separated from Ohonophyllum. One
will not work long, however, before he encounters intermediate forms,
the disposition of which will have to depend upon mere individual
opinion. These make it all the more necessary that our generic charac-
ters be definitely drawn. We do not turn over our land to our neighbor
simply because the line fence is down in places.

Omphyma, Rafinesque and Clifford, 1820.

The type of this genus is 0. turbinata, Fougt., sp.; several Gotland
specimens of which we have examined along with other foreign and
American forms, among which is a series from point. Detour and Drum-
monds island, lake Huron, in excellent state of preservation for study.

The general shape of the corallum and calyx is, as in Chonophyllum,
short conical, turbinate, or conico-eylindrical, with basin-like calyx and
explanate margins. There seems to be no outer covering which can lie
differentiated into a theca and an epitheca, but a single, protective.
epithecal covering, showing plainly through it the body structure of the
corallum. The best preserved specimens show that it was deposited in
exceedingly fine encircling bands or ridges, suggesting the weather-
boarding on the side of a frame house. The so-called heavy accretion-
ridges of growth do not arise from the epitheca, but from successive con-
tractions and expansions of the corallum itself. Likewise the strong and
characteristic radiciform processes come from neither epitheca nor wall.
but are expansions of the body structures.

The corallum is made up of a series of superposed cell-cups, which
form numerous horizontal tabulae through the central area. The septa
are formed by radial infoldings of these continuous cups, sometimes so
sharply bent as to form thin septa in the outer area. Usually, however,
the septa here are broad and angular, >'. e., show a sharp median ridge
giving a roof or tent shape on the upper side. No supporting growths
are developed. When viewed in vertical tangential sections these cup-
Layers are seen to curve downward through the interseptal cavities, from
septum to septum, forming a series of irregular scallops, concave upward
through the interseptal cavities, the upturned points marking the posi-
tions of the septal ridges. \u radial sections, giving side views of these
layers, they are seen to have an additional scalloped structure, now con-
vex upward, and forming coarse irregular vesicles. It is thus seen thai
thesepta and tlic interseptal cavities are not clearly differentiated ;is in

\\\ Vll-I'.i i.i. i. n I, So, \„.. \ ,,i . : 1801

278 W. II. SIIERZER — THE GENUS CHONOPHYLLVM.

the typical Chonophyllum and in the rugosa in general, although from ad-
ditional deposits of calcium carbonate a nearly lamellar septum may at
times be formed.

The septa typically terminate some distance from the center, leaving a
broad, flat central area. In certain specimens the sharp septal foldings
of the cell-cups may continue to near the center as low ridges upon the
tabula?. Four fovew are developed in typical forms, but generally one
only is at all distinctly defined. The broad longitudinal bands on the
cpitheca mark the positions of the interseptal cavities.

The following points of structure will then ordinarily serve for the
separation of Omphyma from Chonophyllum :

1. Strong radiciform processes.

2. Broad, well developed tabula?.

3. Infolding of the cell-cups to form sharply crested or angular septa.

4. Absence of supporting processes.

5. The coarse, subvesicular structure of the interseptal cavities.

6. The generally broad, smooth central area.

7. The presence of one or more fovea?.

8. The broad costal bands representing the interseptal cavities.

Ptychophyllum, Edwards and Haime, 1850.

The type of this genus, as given by the founders, is P. stokesi, E. and H.,
from Drummonds island, lake Huron. Owing to the development of
radiciform processes, similar to those found in Omphyma from the same
locality, Dr. Rominger has redescribed this species as Omphyma stokesi.*
According to this authority, forms in all other respects similar to P
patellatum, from Gotland, which Zittel gives as the type,f occur at the
falls of the Ohio with similar processes.^ We have been able to examine
a few specimens of these two species from the typical localities.

The form of corals referable to this genus is, in general, similar to those
of Chonophyllum and Omphyma. In P. patellatum the catyx margins are
often strongly and irregularly reflexed. The epithecal covering is gen-
erally strong and persistent. One fovea is present, at times becoming-
very distinct. The general structure of the corallum, as regards the
formation of the cell-cups and their radial infolding to form the septa, is
as has been described for Omphyma. We have then angular septa in the
outer area, gradually becoming thinner toward the center, where they
are twisted into a false columella and form an elevation in the calyx.
This columella was regarded by Edwards and Haime as distinguishing

*Geol. Surv. Mich., vol. iii, pt. ii, 18TC>. pp 119-120.

fHandb. der Pal., vol. i, 1880, p. 22:1.

' 1 leol. Sun. Mich., vol. iii. i>t. ii. L876, p. 120.

DIAGNOSTIC FEATURES OF ALLIED GENERA. 270

this genus from ChonophyUum* Nearly or quite as much twisting, how-
ever, may occur in 0. ponderosum, so that this character alone cannot be
relied upon for their separation. No spicules or supporting growths are
found in these type forms. Distinct and, at times, strong tabula? are
found in the central area. The layers curve downward between the septal
ridges and form coarse, subvesicular structures in the outer interseptal
cavities, just as in Omphyma. The broad bands upon the epitheca cor-
respond to the interseptal cavities and the fine, longitudinal grooves mark
the position of the septa.

The following details of structure will ordinarily serve for its complete
separation from ChonophyUum:

1. The more persistent epitheca and occasional radiciform process.

2. The well developed tabulae through the central area.

•'!. Cell-cups forming sharp or angular septa by their radial infoldings.

4. Absence of supporting growths.

•">. False columella and common elevation of the bottom of the calyx.

(>. The coarse subvesicular structure of the interseptal cavities.

7. The generally distinct fovea.

8. The broad longitudinal bands upon the epitheca representing the
interseptal cavities.

We have met a collection of some 7 or 8 specimens from the Helder-
berg group, of Kentucky, 40 miles south of Louisville, in which the
characters of these two genera are to some extent combined. They have
an irregular Ptychophyllum growth, epitheca well preserved, a spongy
columella projecting from the bottom of the pit, one well defined fovea
and, occasionally, radiciform processes. ( )n the other hand, the septa, as
^■<-n in the outer area of the calyx, are not angular but rounded and
convex as in ChonophyUum, and the broad longitudinal bands mark the
position of the septa. Unfortunately the specimens are so solidly silici-
fied that but little of their actual structure can be made out. Basing our
judgment simply upon the external characters, we prefer to assign these
forms to PtychophyUum.

Cyathophyllum, Goldfuss,1826.

The simple forms of this genus are usually readily separated from
Ch&nophyllum by the lamellar septa and the development of tabulae.
Simple forms, however, of the species still commonly known as Cyatho-
phyllum helianthoides, Goldf., are more closely related, ami it may he well
to separate the two, qow that a form of ( 'honophyllum is known so similar
in general appearance. These are turbinate, with regularly and strongly

* Bril Foss, < lor., pt. i, L850, p. I six.

280 W. H. SHEKZER — THE GENUS CHONOPHYLLUM.

reflexed calicinal margins, leaving a monticulose rim around the central
pit. The fovea is obsolete or merely indicated. A thin epithecal cover-
ing is present which shows the broad bands and narrow grooves arranged
as in Omphyma and Ptychophyllum. The septa, as seen in the calyx, are
thin about the pit but broad and angular in the outer area. They are
<>t' two orders, the secondaries terminating at the pit and the primaries
reaching the center without any decided twisting. Cross-sections show
these septa to be thin and lamellar, becoming nexuous and ill defined
in the outer area. In this region they are at times strongly earinated.
the lateral plates either in corresponding position on opposite sides of
the same septum or alternating in position. Vertical tangential sections
show the thin, fiexuous septa with delicate plates arching downward
from each side to the center of the interseptal cavities, generally placed at
the same height on opposite sides of the same septum and giving an ap-
pearance suggestive of the Chonophyttum septal structure. Considerable
irregularity occurs in these layers and. at times, continuous horizontal
plates are introduced which may be traced across a number of septa, in
radial sections these plates give with their cut edges a series of parallel
lines curving upward and outward from the center, while the coarser
carinse cross them at right angles downward and outward from the
center. A well defined vesicular structure occurs in the 1 »r< >ad interseptal
cavities. The tabulae are poorly developed through the central area.

It may be distinguished from Chonophyttum then by the following
points of structure :

1. The lamellar septa.

2. The much broader interseptal cavities.

3. More complete tabulae.

4. The carinal structures.

•5. The broad longitudinal ridges on the epitheca representing the
position of the interseptal cavities and the narrow lines the septa them-
selves.

6. The general form of these corals distinguishes them from all species
except 0. pseudohelianthoides.

Horizons and Distribution.

The only known European forms are C. perfoliatum and C. ]>■« udohi li-
anthoides. Goldfuss' specimen of the former is from the Upper Silurian
(Niagara) of the island of Gotland, while Edwards and Haime's speci-
mens were collected from the Devonian rocks of Brulon, France, and
Torquay. England. The latter species is from the Upper Silurian of
Conjepruss, Bohemia. The remaining species are entirely American, as

DIAGNOSTIC FEATURES OF ALLIED GENERA. 28]

these two are exclusively European. C. magnificum is the most abundant
and widely distributed of any of these. According to Dana, it is charac-
teristic of the Corniferous.* It was obtained by Billings from Walpole.
township, Canada West, and by Rominger and others from the Upper
Helderberg group of Mackinac island ; falls of the Ohio ; Charleston land-
ing, Indiana; and distributed through the drift. C. belli is from the
Upper Silurian (Clinton; of Manitoulin island, lake Huron. C.pondero-
mm " occurs rarely in the Upper Helderberg limestones, but is abundant
in certain layers of the Hamilton group of Thunder bay." It occurs also
in the same formation at Little Traverse bay, and has been met with in
the drift. C. greenei is from the Niagara limestone near Louisville, Ken-
tucky.

The range of the genus is thus through the Upper Silurian and two
lower divisions of the Devonian, reaching its maximum development in
the Upper Helderberg. Ushered into the warm molluscan seas, surviv-
ing the changes which inaugurated the Devonian, finding here conditions
most favorable for its development, by the close of the Hamilton its life
energies had been spent, and, shrouded only by. the sea bottom's slime
and ooze, it passed from scenes of active existence.

Note: In replyto a letter of inquiry concerning the structure of certain of these corals, Professor
Jamos Hall writes as follows:

" In regard to Chonophyllum magnificum, I may say that I know no other coral having the same
type nt structure. 1 have had slices cut from well preserved specimens in several directions, ami
all show a peculiar membraniferous structure such as I have been unable to obtain from any
other cyathophylloid corals or from any other coral which I have examined. When I referred
species to Chonophyllum I had not made sections for critical study. I have since concluded that
Chonophyllum niagarense should 1»- referred to Cystiphyllum, though this one and some other forms
present a very unusual appearance for that genus. Of C. (Ptyehophyllum) ellipticum, I do nut at this
moment recall the structure. All these specimens are now in the American Museum of Natural
II istory, in tie- city of New York, and have been out of my hands for sixteen years.

" I cannot at this moment recall the characterswf C. vadum and C. eapax, nor do I think I have
had sections made of them. I cannot speak positively, but 1 greatly doubt whether they will shew
the peculiar superimposed membraniform layers or tissue characteristic of C. magnificum."

New YoitK State Museum, December 26, 1893.

* Manual of Geology. 1880, p 261.

Explanation of Plate 8.

Figure 1. — Photograph of the original Gotland specimen figured by Goldfuss and
now deposited in the museum of the university of Bonn; natural

size. Very kindly prepared by l>r. Carl Schhiter.

Figure 2. — A vertical section of ChonophyUum maghificum through the outer area,
showing the septa formed of delicate superposed layers, ruder a
magnifier the flat faces of the supporting processes may be seen as
they pass upward through the successive septal lamina'. Between
the broad septa are the narrow, vesiculose interseptal cavities. Mag-
nified 2 diameters.

Figure 3. — A view of the under side of the septal layers taken from a large drift
specimen of C. magnificum. The form and arrangement of the sup-
porting processes, as seen in cross-section, are here shown. In two
places near the top of the figure the layers in adjoining septa are
seen to be 'continuous through the intervening interseptal cavity,
arching upward and assisting in the formation of the vesicular
structure. Magnified 2 diameters.

Figure 4.— A view of the narrow interseptal cavity, showing the vesicles in C.
magnificum. The coarser vesicles are probably formed by the septal
layers as shown in figure 3. Magnified H diameters.

Figure 5.— Much of the structure of C. magnificum is shown in this figure. The
lower portion is the base of the specimen and the upper is the outer
edge of the calyx, the section being vertical and very near the center.
Near the top of the figure, along the upper side, are shown the vesi-
cles of the interseptal cavity, and below them a side view of the
septal layers and the edges of the supporting processes. A view of
the side face of the septum, with its blunt granulations, appears over
the middle third of the figure, while at the bottom is seen the thin,
angularly wavy septa of the central area. The irregular transverse
leaflets, instead of tabulae, here till the interseptal cavities. Magni-
fied l1, diameters.

Figure 6.— ChonophyUum pseudohelianthoides, n. sp. Upper Silurian, Conjeprussj

Bohemia ; natural size.

Figure 7. — ChonophyUum greenei, n. sp. Niagara, Beargrass creek, Louisville, Ken-
tucky : natural size.

.I'M',

BTILL GEOL. SOC

VOL 3, 1891 PL 8

THE GENUS CHONOPHYLLUM.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 283-300, pl. 9

THE PRINCIPAL MISSISSIPPIAX SECTION

CHARLES R. KEYES

ROCHESTER

PUBLISHED BY THE SOCIETY

Ji \h, 1892

ILL. GLOL. SOC. AM.

^j™ Pl^CIPAL n^I^I^IPPIAI

v;\.^.-, ^„

\\«"b^V,^v.^ *>w.

?/ipeGiraril£mj

t.«V VA^W.

c • {Hi"-izL.r,ta.l—l,t.c/i.= 3m,la
OCdiC <

I Vet-tt

ttca.2— i^cA =* /svject

Cu<.,V«..- SV

CU W e.ve >.-lJ«V..

fv^,W.,V.^ w

VOL. 3, 1891. PL 9.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP. 283-300, FL. 9 JUNE 3, 1892

. THE PRINCIPAL MISSISSIPPIAN * SECTION.

BY CHARLES R. KEYES.

{Presented before tin Society August 25, 1891.)

( !( >NTENTS.

Page

Introductory Remarks 283

Typical Sections along the Mississippi River 284

The Kinderhook Beds 287

I >efinition 287

Louisiana Limestone 289

Hannibal Shales 289

Chouteau Limestone 290

( >sage Limestones 2'.H)

Definition and general Relations -"•",

Burlington Limestone 292

Keokuk Limestone 292

Warsaw Beds 293

St. Louis Limestones 294

Kaskaskia or "Chester" Beds 295

Aux Vases Sandstone 295

Kaskaskia Limestone and Shales 296

Coal Measures 297

Recapitulation 298

Introductory Remarks.

.More than half a century has passed since the rich and varied faunas
of the later Paleozoic rocks of the continental interior firsl began to attracl

attention. From the beginning an exc lingly active and ever-growing

interesl was taken in the various forms of ancient Life represented, and.
as a matter of consequence, the geological history of the region was
approached from the biological rather than the stratigraphical side.

* The term Mississippi re used i tituto Cor "Ion i ncrally

applied now to ci rti » I in the Mississippi vulley. The mime was originally suggested in this

by Alexander Winn hoi I, and has recentlj mewh il i lified ind applied by II S. Wil

Bull i - Gool -hi . no. 80, 1891, p. I 10

WW ill i:. ii . .;,. \m Vol.. ; 1891 (.283

"2S4 C. R. KEYES THE PRINCIPAL MISSISSIPPIAN SECTION.

Especially was this the case along the line of the Mississippi river, when'
the most important exposures of the strata in question occur.

The relations of the most important horizons of the lower Carboniferous
in the upper Mississippi valley were early made out by Owen and others,
and although Owen'.- views underwent considerable change during the
dozen years that he was engaged in studying these rocks, his subdivisions
have been practically the basis of all subsequent classifications. In the
main they have been adopted everywhere, notwithstanding the fact that
a considerable diversity of opinion always has existed in respect to the
minor stratigraphical details.

In the naming of the several assemblages of beds, the leading and most
widely known terms that have been applied have been taken from locali-
ties situated on the " Father of Waters." The Mississippi section, there-
fore, becomes the most important of all in the correlation of the lower
Carboniferous rocks of the great interior basin. Fortius reason it was
that recently all the original localities were visited, the various exposures
examined in detail, their relationships with each other and with the over-
lying and underlying strata particularly noted.

The nominal history of the major subdivisions of the Paleozoic of the
Mississippi basin need not be reviewed in this place. Suffice it to men-
tion that the term Subcarboniferous had in the beginninga very different
meaning from what it has had of late years. As originally proposed by
Owen * the name was used merely to indicate an indefinite series of limc-
-t.iues below the coal-bearing strata of the interior. Subsequently f the
same author limited the formation below to the blue, fossil-bearing lime-
stones now known as the Cincinnati beds. In was in 1847, when Owen
and Norwood J gave the "black slates'' as the upper limiting member of
the Devonian, that " Subcarboniferous" was still farther restricted, thus
for the first time giving the name Subcarboniferous the meaning which
has been generally attached to it of late years.

The most familiar name- assigned to the subdivisions of the Carbon-
iferous along the Mississippi river are ten in number, viz: Chouteau,
Kinderhook, Burlington, Keokuk. Warsaw, St. Louis. Ste. Genevieve,
Chester, Kaskaskia, Coal Measures.

Typical Sectioxs along the Mississippi Rivep.

A few of the most characteristic sections have been selected for notice
here, and their lithological details are briefly explained. By comparison
with the general section (plate 9) it is thought that the stratigraphical

* Rept. Geol. Rec. Indiana, is:;: 1 1839), p. 1^.

t Rep. nu .Min. Lands of the United States, 1840, p. 14.

f Researches "n the Protozoic and Carb. Rocks of ci ntral Kentucky during the year 1846 (1847)

SECTIONS IN IOWA. 285

relations according to the present understanding can be pointed out in
the briefest possible manner. These sections are taken at places where
the must minute and satisfactory information is to be obtained, and they
assume their names from these localities. They are all marked on th i
general section.

The Burlington Section.

Feet.

10. Impure and often somewhat clayey thinly bedded limestone with chert

nodules and seams 20

'.>. Gray, coarse grained encrinital limestone with occasional clay partings

and some flint :'°

s. butf calcareous and siliceous shales with thin limestone ami Hint bands. . 23
7. Brown and gray encrinital limestone, compact and heavily bedded, with

thin clay partings 27

Ik Rather soft buff limestone, probably somewhat magnesian, apparently

sandy locally '

5. Gray oolite -±

4. Soft, fine grained, yellow sandstone, highly fossiliferous 6

:;. Gray, impure limestone, fragmentary, with often an oolitic band below. . 9-1::
2. Soft, line grained bluish or yellowish clayey sandstone passing into sandy

shales in places , ■ : 20-30

1. Blue clay-shale, fossiliferous, shown by borings to extend -30 to 100 feet

or more below the water level ; exposed 50

All beds below number G are regarded as Kinderhook. Numbers 7 and
S form the lower Burlington limestone; numbers '.land 10 the upper
Burlington limestone.

Keokuk Exposures: Tabor's Saw-mill.

Feet.

'.). Drift and loess 1(>

s. Soft brown or yellowish sandstone passing into a finegrained conglomer-
ate in places, irregularly cross-bedded and lying un conformably upon

the next ; exposed ht

7. Blue and ash-colored breccia led limestone, indistinctly bedded locally and

passing elsewhere into regularly bedded layers 25

<;. Brown, impure arenaceous limestone, heavily bedded 4

."). Blue, calcareous clayey shale 1°

4. Impure limestone, massive and weathering brown <

:;. ( lav-shales with occasional limestone bands and abundant little crystal

grottoes — the "geode-bed" 35

2. Thinly bedded somew hat shaly limestone 5

1. Blue encrinital limestone, heavily be, Med and more or less highly fossil-
iferous ; exposed '•'

Below number I of this section is the Keokuk group of Hall: 1 to 6,
inclusive, form the Warsaw of the same author : while number 7 is the St.

286 C. R. KEYES — THE PRINCIPAL MISSISSIPPIAN SECTION.

Louis limestone reposing unconformably upon the brown massive layer
number 6, and with the Coal Measures, number 8, superimposed uncon-
formably upon it.

Warsaw Section.

Feet.

6. Ash-colored brecciated limestone , 25

5. Buff calcareous gritstone, fossiliferous 8

4. Blue clay-shale with thin bands of impure limestone 2.3

3. Compact buff limestone with encrinital layer above 0

2. Blue clay-shales ; " geode-bed " 30

1. Thinly bedded encrinital limestone, highly fossiliferous ; exposed 15

Numbers 1 to 5 are regarded as Keokuk. Of these numbers 3, 4 and 5
are the typical Warsaw of Hall. Number 6 belongs to the St. Louis.

Louisiana Exposures.

Feet.

15. Soil 2

14. Compact yet thinly bedded encrinital limestone, with considerable gray

and brown chert 50

13. Massive, white encrinital limestone, coarse grained 12

12. Brown encrinital limestone with irregular chert bands and thin clay

seams occasionally 20

11. Very heavily bedded white encrinital limestone 11

10. Brown encrinital limestone, somewhat sandy in places ; earthy and dis-
integrating on exposure to the weather 15

9. Fine grained buff limestone 15

8. Brown sandy shales 12

7. Green clay-shales 60

6. Thinly bedded compact buff limestone, in layers from 4 to 6 inches in

thickness, with a thin and sandy highly fossiliferous seam at the base. 50

5. Blue clay-shales 2

4. Black fissile shale 4

.">. Compact, massive buff limestone 10

2. ( iray oolitic limestone 5

1. Blue clayey shales with numerous thin limestone bands, rich in fossils;

exposed 60

All above number 9 belongs to the Burlington limestone, and the beds
from numbers G to 9, inclusive, to the Kinderhook. Number 9 is the
Chouteau limestone of Swallow ; numbers 7 and 8 the Vermicular sand-
stone and shales of the same author; and number 5 is the Lithographic

limestone.

St. Louis Section.

Feet.

blue and gray limestone, compact, rather heavily bedded, more or less highly

fossiliferous, with thin marly partings; exposed to water level L25

SECTIONS IN MISSOURI AND ILLINOIS. 287

Ste. <u nevieve to Ste. Mary*

Feet.

S. Soil 3

7. Soft, yellow ferruginous sandstone, exposed 15

li. Clay-shales and heavily bedded blue limestone 125

5. Yellowish sandstone (Aux Vases river) 70

4. Bluish thinly bedded limestone (Ste. Genevieve) 45

:!. Rather heavily bedded blue and ash-colored limestone with marly part-
ings, showing cross-bedding in places ; oolitic and cherty locally 135

2. White oolite, fossiliferous 15

1. Massive, compact limestone, white in color and highly fossiliferous; ex-

posed 50

Number 1 is probably upper Keokuk. Numbers 2 to 4 belong to the
St. Louis group; while number G is the Kaskaskia. Number 7 is the
basal sandstone of the Coal Measures.

Chester Section.

Feet.

8. Furruginous sandstone with plant remains ; exposed 25

7. Green and blue clayey shales with occasional limestone bands 10

6. Gray limestone, more or less nodular and impure 45

5. Green and blue clayey shales with thin limestone layers, highly fossil-

ifer< »us in places 45

4. Heavily bedded, compact encrinital limestone with clay partings 3

3. Drab fossiliferous shales with thin calcareous seams 4

2. Dark drab compact limestone 4

1. Heavily bedded blue and gray limestone ; above water level 75

The Kinderiiook Beds.

Definition. — There seems to be a general unanimity of opinion as
to the propriety of regarding as a distinct subdivision the lower Carbon-
iferous rocks of the Mississippi basin below the Burlington limestone.
The upper line of demarkation is easily recognizable throughout its geo-
graphic extent. Its lower limit, however, has not been made out satis-
factorily over the entire area of its occurrence ; but in many places the
group of strata is known to rest on the "black shale" so well developed
in Tennessee and generally regarded as Devonian in age. Forthegroup
of beds in question, or parts of the group, various names have been given.
Bui their historical consideration need not be dwelt upon at Length here.
Whatever may be eventually the most, appropriate term to apply to this
section, it seems advisable for the present to retain Meek and Wbrthen's
name for these rocks as exposed along the line of the Mississippi river.

*The sections of Ste. Gene\ ieve, Chester and Louisiana are from personal notes made in connec-
tion with the i loi ii al survey of Mis i and arc incorporated in this placi bj the kind perm is

h i of thi tute gcologi i Mi Arthur Winslow

2S8 C. R. KEYE5 — THE PRINCIPAL MISSISSIPPIAN SECTION.

Among the earliest references to the rocks of this group in the conti-
nental interior is made in connection with Owen's explorations in south-
eastern Iowa.* This author called some sixty feet of ash-colored shales,
exposed above the level of the water in the Mississippi river to the base
of the encrinital limestone at Burlington, the " argillo-calcareous group,"
and regarded them as belonging to the lower part of the Subcarboniferous.
These shales were actually a portion of the median member of what
Swallow,! in Missouri, termed the "Chemung" group. This group was
divided into (1) the Chouteau limestone, (2) the Vermicular sandstone
and shales, and (3) the Lithographic limestone. Within the limits of the
region under consideration these three divisions are quite persistent and
easily recognizable over a wide area. For present convenience the last
two members may be termed more appropriately the Hannibal shales
and the Louisiana limestone respectively, since at these places in eastern
Missouri they are exposed in their full development.

Throughout Iowa, Illinois and Missouri, at least, and perhaps in other
states also, wherever the Kinderhook rocks are exposed, its members, as
here designated, will always be recognized to a greater or less extent,
particularly in faunal studies. Over all the three states named these
subdivisions are sharply defined lithologically, except possibly toward
the northern known limits, though there these rocks have received very
little or no attention. At the present time it seems very probable that
the third or lowest member — the Louisiana or Lithographic limestone —
will find a closer relationship with the Devonian than with the Carbon-
iferous, and that eventually it will he regarded as the capping stratum
of the former over all the territory contiguous to the Mississippi.

In 1858 Hall still continued to regard the Burlington, Iowa, section
below the oolite layer as Chemung. But he also included in the group
some yellow sandstones occurring fifty miles to the northward, which
Calvin J has recently proved conclusively to be of Devonian age.

Although Owen had referred the shales lying immediately below the
limestone at Burlington. Iowa, to the Subcarboniferous more than a
decade previously, Meek and Worthen,§ in 1861, were the first to prove
beyond a doubt that the faunas of the rocks along the Mississippi river
between Burlington and St. Louis and lying between the "black shale"
and the Burlington limestone have much closer affinities with those of
the overlying strata than with those below, and therefore that the rocks
in question properly belong to the lower Carboniferous series. The name
" Kinderhook " was then proposed for the formation.

*Geol. Sur. Wisconsin, Iowa and Minnesota, 1852, p. 92.

t A ii ii. Rep. Geol. sur. Missouri, 1855, p. 103.

;.\m. Geo4., vol. iii, 1889, p. 25.

f.Vni. .lour. Sri.. 2d series, vol. xxxii, p. 228.

PRIORITY OF TERM " KINDERHOOK." 289

Soon afterward Worthen * published further details, especially in re-
gard to the typical locality, Kinderhook, Illinois. Various sections in
the neighborhood were fully described, leaving no doubt as to the real
limits that were intended to be assigned to theterrane. On the opposite
side of the river, in Missouri, the exposures are almost continuous for
more than thirty miles and show well the relations from the "black
shale" to the upper division of the Burlington limestone.

In the Iowa section Whitef recognized as Kinderhook the Burlington
rocks previously called Chemung, together with a few feet of what was
once considered as belonging to the superimposed stratum.

The " Chouteau " group takes its name from the leading member of
this three-fold division, the Chouteau limestone. The application in this
sense was first made by Broadhead,'j who used the term to cover the
same limits as Swallow's " Chemung " in the earlier Missouri reports.
Very recently the name apparently has been extended by Williams ^ to
embrace the lower Carboniferous littoral deposits (Waverly grits, etc ) and
the open sea deposits of argillaceous and calcareous material (Kinderhook
shales and limestones).

From the foregoing it appears that in the states bordering the Mis-
sissippi river the term Kinderhook has priority in the naming of the
lower member of the lower Carboniferous as now generally understood.
Whether or not Waverly or Marshall, as the rocks of probably the same
age in Ohio and Michigan are called, should replace Meek and Worthen's
name remains to be seen. These were probably littoral deposits. Both
lithologically and faunally they are sufficiently distinct from the more
western deposits to make a separate designation desirable.

Louisiana Limestone. — Swallow's Lithographic limestone is exposed best
perhaps at Louisiana, in Pike county, Missouri, where it attains a maxi-
mum thickness of more than GO feet. As its early name suggests, its
texture is very similar to that of the stones used in lithography ; hut this
peculiarity does not extend throughout its entire range. It is usually
rather thinly bedded, the layers being from four to six inches in thick-
ness, and wherever exposed stands in high, mural escarpments, with
every appearanceof artificial masonry. The lower layers are moreor less
arenaceous, ami yield numerous fossils. At Louisiana tins limestone
rests on a dark clayey shale, whose thickness is about six feet, and this
again on ;i compact, buff, magnesian Limerock, probably of Silurian age.

Hannibal Shales. — The Hannibal shales ( Vermicular shales o{' Swallow )
have a maximum thickness of aboul 75 feet :it the typical Locality. In

*Geol. Sur. Illinois, vol. i. 186C, p. 108.
| * reology nl' lnu,i. Mil. i. 1870, \>. 192.

i ■■■Hi Sur Missouri, 1874, |>. 2G.

Bui I S. < Seol Sur . no. 80, 1891, p 169

290 C. R. KEYES — THE PRINCIPAL MISSISSIPPIAN SECTION.

Missouri the tipper portion is sandy in places and forms often a rather
compact, shaly sandstone, becoming harder northward, where it assumes
the character of a substantial sandrock. The latter is apparently entirely
absent in the southwestern part of the slate Downward, the shaly sand-
stone rapidly looses its arenaceous character and passes quickly into
bluish or greenish clay-shales winch appear remarkably uniform over
broad areas. At Burlington, Iowa, recent excavations show a thickness
of more than 70 feet, while borings indicate a thickness of double that
figure. Toward its known limit southward, in Greene county, Missouri,
for example, more than 50 feet of these shales have been observed, and
there is every reason to believe that they are considerably thicker.

It is commonly supposed that these shales are destitute of fossils, bid-
late excavations at various places have disclosed rich faunas of a most
interesting and instructive nature.

Chouteau Limestone. — The upper member of the Kinderhook is a fine
grained, compact limestone, buff in color, and usually more or less im-
pure from an admixture of clayey material. At Hannibal and Louisiana
it has a thickness of from 10 to 15 feet, apparently thinning out rapidly
northward. It is probably represented at Burlington, Iowa, by a few-
feet of buff calcareous layers lying at the base of the great limestone at
that place. At Legrand, in Marshall county, Iowa, the 50 feet of buff
magnesian limestone immediately underlying the Burlington may, per-
haps, be a northward extension of the Chouteau. Southward in Missouri
the bed in question increases in thickness until it attains a measurement
of 100 feet or more at Sedalia, and about 50 feet in the vicinity of Spring-
field in the southwestern part of the state. Near Ste. Genevieve there
arc probably from 75 to 100 feet of this limestone. It is quite possible
that in the northwestern part of this state, far below the Coal Measures,
this limestone attains even a much greater thickness.

Osage Limestones.

Definition and general Relations. — From a purely paleontological stand-
point, the advisability of including the Burlington and Keokuk lime-
stones under a single name was pointed* out several years ago. For
this long needed term Williams f has proposed "Osage."

Owen's enerinital limestone embraced practically the same beds that
were afterwards called the Burlington,; and his lower Archimedes cor-
responded to Hall's Keokuk group below the geode bed. Shumard
seems to have used the term "Enerinital limestone" in a variety of

*Am. Journ. Sei., 3d scries, vol. xxxviii. 1889, pp. 18G-193.
t Bull. U. S. Geol. Sur . no 80, 1891, p 169.

DIFFERENTIATION AMONG THE CRINOIDS. 201

senses — sometimes referring to the Burlington alone, sometimes to both
Burlington and Keokuk, and often to the Burlington and a part of the
Keokuk. Partly on lithological grounds, but chiefly for paleontological
reasons, the " Osage " may be regarded as made up of three members —
upper, middle and lower — coinciding essentially with the Keokuk and
the upper and lower Burlington limestones. In regard to the fossils of
the three horizons, the most conspicuous differences are found among
the crinoids, which form such a characteristic feature of the several
faunas. These general differences were first suggested by White* and
quite recently f they have received further attention. They may be
restated briefly here: Those species from the lower Burlington are of
small size, delicately constructed and highly ornamented. In the upper
division of the Burlington the peculiar delicacy pervading the forms of
the lower bed is absent or has assumed a ruder character, while in the
Keokuk the crinoids are characterized by large size, rough and massive
const ruction, bold and rugged ornamentation, and a conspicuous exag-
geration in many structural details. The last consideration is of great
interest, since it appears that in general the exaggeration of anatomical
features is indicative of important biologic changes in that particular
zoological group in which such extreme developments take place.

It is apparent from a close study of the crinoids (and in a somewhat
less marked degree among other zoological groups) that there was an
abrupt change of physical conditions at the close of the Keokuk epoch.
One-half of the Carl »< >niferous genera had become extinct ; the great group
Camerata bad passed away, with the exception of the Hexacrinida1 and
a few depauperate forms of several other genera whose existence was
quickly brought to a close. A large proportion of the genera in the
extensive section Inadunata had disappeared; of those groups which
survived to the close of the period, a diminutive species was the sole
representative of the Larviformia, while of the great group of the Fistulata
only the ty] deal genus (including several subgenera) of the Poteriocrinida'
extended through the entire lower Carboniferous.

As already stated in another place, the sudden extinction of a large
proportion of the crinoidal and other forms of life at the close of the
Keokuk is certainly suggestive of a series of wide-spread changes in the
geographic and bathymetric extent of the great interior sea ; and there
is sullicieiit evidence to indicate that at the close of the Keoknk and
during the early part of the so-called Warsaw the northern coasl line of
the broad shallow gulf moved rapidly southward, and that this movement
was soon followed by a slight depression. The St. Louis waters then
pushed northward again, in some places several hundred miles.

* J ii. Boston Soe. Nal II i t., vol. vii, pp. 224, 225

• ■- Am. Jonm. Sei., 3d series, vol xxxviii 1889 pp 191 L92

XXXIX B i 3oi \ m \ "i '■ I'M

292 C. R. KEYES THE PRINCIPAL MISSISSIPPI AN SECTION.

Burlington <iAmestone. — The lithological characters of the Burlington arc

remarkably constant over broad stretches of territory, and they are practi-
cally identical over its entire extent, so far as it has been traced accu-
rately, from northern-central Iowa to western Illinois, southwestern Mis-
souri and Arkansas. Everywhere it is the same coarse grained encrinital
limestone, intensely white and quite pure in certain layers. For the most
part its geographic distribution is west of the Mississippi river. East of
the stream the typical exposures of this rock are unimportant and un-
known beyond the immediate vicinity of the great watercourse.

Keokuk Limestone. — The upper member of the Osage, on the other hand,
has its distribution chiefly on the eastern side of the " Father of Waters."'
c( tvering a wide area in Illin< >is, Indiana, Kentucky and Tennessee. West
of the river the most typical exposures are in southeastern Iowa and
northeastern Missouri. At Boonville, in central Missouri, where these
rocks have been reported, the faunas contained do not indicate the true
Keokuk. In the southwestern part of the same state no typical Keokuk
lias been observed, so far as is known. The encrinital limestone of that
region, which has been thought by some to represent both the Keokuk
and Burlington limestones of the more northern localities, appears to be
the latter alone. Extensive collections of fossils made in various parts
of the formation show few species that can 'be regarded as belonging^*)
the true Keokuk. This is all the more remarkable from the fact that a
vertical section of the Kinderhook and Burlington beds of the region is
essentially identical, lithologically, with the one of northeastern Missouri.
After all, the upper member may be present, for the recent personal
observations were not conclusive enough to preclude its existence entirely.

There is, however, another very suggestive consideration bearing upon
the relations of the Keokuk and Burlington limestones which is worthy
of notice. It was strongly impressed some years ago while engaged in a
study of the Carl toniferous echinoderms of the Mississippi 1 >asin. Accord-
ing to this inference it appears that the lower portions of the Keokuk and
Burlington rocks were deposited nearly at the same time but in practi-
cally separate basins, the barrier being approximately along the line of
the present Mississippi river. As the obstruction Avas gradually removed,
the animal forms of the two districts mingled more or less completely,
and those of the eastern area being better adapted to the changing condi-
tions displaced the old occupants of the eastern portion of the Burlington
territory as the sea became gradually deeper, eventually replacing them
altogether; so that in the area of the typical localities of these rocks a
succession of faunas is represented that is not shown elsewhere1. Thus
the so-called Keokuk overlapped, by degrees, the Burlington, and while
the fauna of the upper Keokuk was living where portions of Iowa and

RELATIONS OF FAUNAS TO ENVIRONMENT. 29

Missouri arc now limited, the lower Burlington forms still flourished in
the waters to the southwest ward j even as far as the present boundaries of
New Mexico.

In regard to the derivation of the Keokuk fauna from the areas con-
siderably east of the Mississippi river line and of the Burlington from
districts west of that limit, a further hint is obtained in an examination
of the various faunas that immediately preceded. Again the crinoids
may come into service. Attention already has been called to the pecu-
liarly fitting role that the stemmed echinoderms play in considerations
of this kind, and to their ornamentation and general structural charac-
ters as shown in the three members of the Osage. Composed of regular
plates, definitely arranged and often highly ornamented, delicate pinnu-
lated arms, and characteristic stems, these organisms were admirably
adapted for recording the changes in the physical conditions of their
environment. The species of the Devonian and the early Carboniferous
in the eastern portion of the Mississippi basin were, with few exceptions,
large, massive, heavily plated forms, coarsely ornamented, and possess-
ing in many cases a peculiar extravagance of structure. An examination
of the species from the Kinderhook and the accessible Devonian of the
western district shows that in great part the forms were all highly and
delicately sculptured, rather frail in construction, and of small size. There
seems to be but little doubt that in the district of southeastern Iowa the
Burlington forms are genetically related to those of the subjacent dej m >sits.
The relationships of the same forms to those of tire rocks immediately
above has always appeared to be only in part genetic. The apparently
direct succession is explicable in many cases on the assumption (which
is very probable) that the barrier alluded to above was only partial,
allowing a certain amount of mingling. The lithological characters of
the strata immediately heneath the Burlington also attest the shallowness
of the water along the line mentioned.

Warsaw Beds. — The Warsaw beds, as defined by Hall :|: and as exposed
at the village of Warsaw, Qlinois, are composed of (1) 10 feet of com] tact,
buff-colored limestone. C_') 30 feet of blue calcareous shales with many
thin limestone seams, and (•".) 8 feet of yellow arenaceous limestone. At
Keokuk, live miles above, all three layers are thinner, and at neighbor-
ing places they exhibit still different characters. Southward the beds
Lose their argillaceous nature and appeal' not to be separable from the
associated Limestones. These layers, together with the geode bed, which
is usually considered the upper member of the Keokuk, may be regarded
as mere local developments to which Little importance is to be attached.
In a quarry a short distance northwest of Rand park, at Keokuk, Iowa,

HJeolog) "i town, pt. i, LS58 p U7.

294 C. R. KEYES — THE PRINCIPAL MISSISSIPPIAN SECTION.

there is a good exposure showing the upper surface of the buff arenaceous
limestone to be water-worn and weathered ; and directly upon the eroded
rock rests 20 feet of brecciated limestone. Whether or not this point can
be regarded as a portion of an ancient land surface older than the St.
Louis limestone depends partly upon the results of further investigation
and partly upon the final decision as to the origin of the brecciated rock.
At Hall's typical locality it is manifest that the Warsaw beds are
I u'opeiiy the superior portion of the Keokuk limestone. This inference is
directly derivable both from the faunal and stratigraphical features, and in
a less marked degree from the lithological nature of the deposits. The
layers passing under this name reported from other localities are now
known to have various relationships with the overlying and underlying
strata. Alleged faunal peculiarities have usually been the chief grounds
for considering the Warsaw as a distinct subdivision of the lower Car-
boniferous. Most writers on the subject have united the beds under
discussion with the St. Louis; a few with the Keokuk. This difference
of opinion has arisen, largely from assumptions made at the places most
thoroughly studied by the respective authors, without due allowance
being made for the varying conditions in separated localities. A careful
comparison of notes and a somewhat extended stud)' in the held show
that the term "Warsaw" has been loosely applied since its original
appearance as a geological name. In the majority of places the so-called
Warsaw is clearly the lower part of the St. Louis limestone. Thus the
investigators above alluded to were perfectly correct in contending that
the '* Warsaw," as they understood it, was really a portion of the St.
Louis. But they made the mistake of claiming that the Warsaw of all
localities is St. Louis. It is apparent, then, that in some places the
so-called Warsaw cannot be separated from the St. Louis limestone ; in
others it is best united with the Keokuk. It seems better, therefore, to
drop the term in its application to a distinct section of the lower Car-
boniferous, or Mississipian series, with a rank equal to the other sub-
divisions here recognized.

'to*

St. Louis Limestones.

Since first recognized by Shumard, little difficulty has been encountered

in locating the St. Louis limestone over a wide stretch of country. Its
northern border is several hundred miles beyond any known exposure
of Keokuk rocks. From this limit nearly to the .Missouri river the lime-
stone is quite thin; hut south of the latter point it rapidly thickens, until
in Ste. Genevieve county, Missouri, it attains a. measurement of more
than 300 feet, and still farther southeastward more than double the thick-

UNCONFORMITIES IN THE CARBONIFEROUS. 205

ness known in the state mentioned. The Ste. < lenevieve limestone, which
Shumard differentiated from the St. Louis deposits near the mouth of
Aux Vases river, a few miles below the old village of Ste. Genevieve,
appears to he merely the upper part of the main group of strata ; and the
fossils contained fully substantiate this view.

The unconformity of the St. Louis rocks upon the underlying strata
in Iowa and the adjoining portions of the neighboring states has been
fully explained by White* The thinness of the limestone has been
alluded to already. This is due partly to the thinning out of the strata
northward and partly to the subaerial erosion prior to the deposition of
the Coal Measures of the region.

Toward its present northern limits the upper part of the St. Louis is
composed of soft, plastic, highly fossiliferous marls, which are well ex-
posed nt Fort Dodge, in the northern-central part of Iowa, and at Harvey,
in the central portion of the state, besides numerous other localities im-
mediately to the southward of the last named place. At Elk cliff, a few
miles from Harvey, as well as elsewhere, the marl has been removed
entirely down to the hard limestone upon which rests directly the strata
of the Coal Measures. Nor is this all : the uneven configuration of the
ancient land surface is further shown by the presence of more than 100
feet of clays and shales, represented a short distance down the stream
(Des Moines river), before the level of the summit of the old limestone
elevation is reached. f

Over all the northern area of the St. Louis a characteristic brecciated
rock is observable. But south of the Missouri river evenly bedded lime-
stones are present, with occasional extensive beds of oolite. In places at
Ste. Genevieve the oolitic limestones present perfect cross-bedding, such
as is commonly seen in sandstones, a. fact which is very suggestive in its
bearing upon the origin of certain oolites.

The fauna! features of the St. Louis are peculiar in many respects, and
quite distinct from those of both the overlying and underlying strata.
particularly from the latter.

K askaskia 01; "Chester" I5ki>s.

Aux Vases Sandstone. — In southern Illinois and southeastern Missouri
the Kaskaskia comprises extensive beds of limestone and shale. Every-
where over this -district these calcareous poi-t ions, which greatly predomi-
nate in the lower part of the group, are underlain by a line grained fer-
ruginous sandrock. This sandstone is recognizable above the city of St.

Geology of Iowa, vol. i. 1870, pp 22i>-229.
I K' ■>'■- : Bill Goo). Soc. Am., vol. a, 1890, p, 287.

296 C. R. KEYES — THE PRINCIPAL MISSISSIPPIAN SECTION.

Louis, where it is a dozen feet or more in thickness ; southward it rapidly
thickens until in the vicinity of the typical locality it attains a maximum
measurement of more than 100 feet.

The true significance of this great sandstone separating the St. Louis
ami Kaskaskia limestones does not appear heretofore to have been under-
stood fully, especially when taken in connection with the absence of
Kaskaskia rocks north of the Missouri river. Here is an extension of
limestone — the St. Louis — that before the Coal Measures were laid down
was greatly eroded over a large part of its area, and over another adjoin-
ing portion having a great sandstone superimposed. This would seem
to indicate that the broad expanse of waters which, during the deposition
of the St. Louis beds, reached nearly to the present northern boundaries
of Iowa had retreated more than 403 miles to the southward. Dry land
existed over a large part of the area formerly covered by the St. Louis
waters, and bordering this continental nia^ arenaceous deposits were
laid down in the shallow littoral waters.

In all the Carboniferous of the Mississippi basin no group of strata
appears to form a better defined natural geological unit than those beds
commonly passing under the name of Kaskaskia or Chester.

The great arenaceous deposit lying at the l>a<e of the Kaskaskia, lime-
stone has been termed the '' ferruginous sandstone " by Shumard and
others. Many observers, however, have confounded it with a lithologi-
cally similar sandrock situated at the base of the Coal Measures and
consequently located on, instead of under, the Kaskaskia. For conveni-
ence in reference and in order to avoid further confusion this great sand-
stone will be called here the Aux Fases sandstone, from the river of that
name in Ste. Genevieve county. Missouri, on which the rock is exposed.
Of course in northern Missouri and Iowa, where the superior member of
the Mississippian series is wanting, the basal sandrock of the Coal Meas-
ures occupies the same stratigraphical position as the lower Kaskaskia
sandstone — that is, superimposed upon the St. Louis.

Kaskaskia Limestone and Shales. — Everywhere over that part of the upper
Mississippi valley in which the Kaskaskia is absent the St. Louis rocks.
as already stated, are weathered and deeply channeled, many gorges
passing downward even to the Keokuk, thus showing pretty conclusively
that these portions of the territory were actually above sea level during a
part of the Kaskaskia deposition. That the northern shore-line con-
tinued to move southward after the Kaskaskia epoch had begun, and
perhaps even until the latter half of the interval had set in, is shown by
the successive attenuation of the several beds and by the deeply excavated
ravines, where soon afterward were laid down the local sandstones and
shales of the Coal Measures. In a number of cases, at least, these hardened

PRIORITY OF THE TERM " KARK ASK I A ." 297

sand accumulations, lying in narrow gorges, have been regarded erro-
neously as local depositions of Kaskaskia grit intercalated in the shales
and limestones. Futhermore, these consolidated sands contain plant
remains, and inasmuch as they have been considered as parts of the Kas-
kaskia,it is quite probable that this will account for some of the reported
discoveries of terrestrial floras in the rocks of the Mississippian scries.

Faunally,and especially stratigraphically, the Kaskaskia, as displayed
everywhere over a broad area adjacent to the line of the principal section.
appears separated from the St. Louis far more widely than any other two
members of the entire Carboniferous in the continental interior.

The term " Chester " has been used by some authors for the beds here
designated as Kaskaskian. There seems to be, however, but little doubt
that the latter name was published some years before Chester made its
appearance in print. To be sure, Worth en, while an assistant of Nor-
wood on the geological survey of Illinois, did suggest, orally or in his
manuscript notes, the name " Chester" for the beds in question as early
as 1853; but the name was known for several years only to members of
Norwood's corps, as Worth en himself says.* It was at least a ddzen
years later before the term was published with definite stratigraphical
significance, and then with the full knowledge that it covered the same
ground as Hall's "Kaskaskia/1 Hall, as early as 1856, read a paper
before the Albany Institute, in which he proposed a classification of the
lower Carboniferous of the Mississippi basin; and two years later he
published essentially the same scheme in his Iowa report,f accompanied
by a clear description of this formation. Kaskaskia necessarily must be
retained, therefore, for the upper member of the Mississippian series in
preference to " Chester." If it is desirable to keep the latter term in
geological nomenclature, it might be advisable to restrict it to the upper
shaly division, which can advantageously be distinguished from the
lower massive limestones, and "Chester shales," as they are now often
called locally, could still be made a useful term.

( !o \l Measures.

Along the line of the general section the Coal Measures occupy an
unimportanl place. The exposures are chiefly of the basal sandstone
and the associated shales which outcrop along the river only at Long
intervals in old gorges and superimposed upon members of Mississip-
pian series. As already intimated, the St. bonis limestone above the
mouth of the Missouri, and a goodly proportion of the Kaskaskia below

i leol -in-. Illinois, vol. i. 18C0, p II.

; I low a, pi. i. 1868, p 109.

298

('. R. KEYES — THE PRINCIPAL MISSISSJPPIAN SECTION.

hat stream, have been land surface-; and were greatly eroded before the
invasion of the coal swamps. In many places throughout the same
region the coal strata rest on older rocks, on other members of the Mis-
sissippian series, and even on the Devonian.

Further consideration of the series is unnecessary here. In one por-
tion of the area under consideration the Coal Measures have been studied
with considerable care and a very detailed section made from near the
ancient land limit seaward a distance of nearly 75 miles. A preliminary
statement of these observations lias been made elsewhere*

Recapitulation.

From the foregoing description it is to be inferred that, on the best
lithological, stratigraphical and faunal evidence now at band, the Mis-
sissippian series embraces tour groups, which may be tabulated as fol-
lows :

Kaskaskia group

St. bonis group

Mississippian series

( >sage group

f " Chester shales." f

" Kaskaskia limestone.'1
( Aux Vases sandstone.

("Ste. Genevieve limestone.'1
! St. Louis limestone.
Warsaw limestone (in part ;
not typical).

[ Warsaw shales and limestone
(typical).
" Geode bed."
K eokuk lim estone.
Upper Burlington limestone.
Lower Burlington limestone.

f Chouteau limestone.
Kindcrhook group -. Hannibal shales.

( Louisiana limestone.

The " Louisiana limestone ,! is layer number 6 of the Louisiana ex-
posures. The "Hannibal shales1' comprise numbers 7 and 8 of the
same locality; probably also numbers 1 and 2 of the Burlington section.
The " Chouteau "' is number 9 of the Louisiana limestones. The "lower
Burlington limestone" embraces numbers 7 and 8 of the Burlington
section; the "upper Burlington limestone11 numbers 9 and 10 of the

* Bull. Geol. Soc. Am., vol 2, 1890, pp. 277-292, plates ix, x.

f The names in quotation marks arc local applications. The Kaskaskia, aside from the basal
sandstone, appears to be a well defined two-fold division, and ii seems advisable to keep the two
members distinct, though special names are not retained for them here. The Si Louis and Kas-
kaskia correspond essentially to Williams' "Ste Genevieve group."

BASES OF CLASSIFICATION. 299

same. The two together form numbers 10 to 14, inclusive, at Louisiana.
The " Keokuk limestone" is numbers 1 and 2 of the Keokuk exposures.
number 1 of the Warsaw section, and probably number 1 of the Ste.
Genevieve outcrops. The "geode bed" appears as number 3 at Keokuk
and number 2 at Warsaw ; the typical ''Warsaw11 embraces numbers 4
to (> of the Keokuk section and numbers 3 to 5 at Warsaw. The "St.
Louis limestone " is represented by number 7 at Keokuk, number 6 at
Warsaw, all of the St. Louis section, and number 3 at Ste. Genevieve,
while number 2 of the same section has been called the Warsaw lime-
stone (not typical). The "Ste. Genevieve limestone" of Shumard is
number 4 of the Ste. Genevieve-Ste. Mary outcrops. The " Aux Vases
sandstone" forms bed number 5 between Ste. Genevieve and Ste. Mary,
and underlies number 1 of the Chester section a few miles north of the
town. The " Kaskaskia limestone" includes numbers 1 to 4 of the
Chester section, and the "Chester shales" numbers 5 to 7 of the same
section. The Coal Measures are represented at Keokuk by number 8, at
Ste. Genevieve by number 7, and at Chester by number S.

The great abundance of fossils in all the members of the Mississippian
series of the interior basin makes the faunal test perhaps the most impor-
tant of all in attempting a rational classification of the rocks of the region.
Heretofore the remains of ancient life found in these rocks have been con-
sidered either from a purely biological point of view, or, in the majority
of cases, from the standpoint of the mere species-maker ; and it is only
within the past few years that large numbers of species taken together
have been compared with one another in order to marshal the confused
collections into orderly arrangement, so that faunas may be studied as a
whole.

The second important consideration to be taken into account in the
present connection is the stratigraphical testimony. In the case of the
Kaskaskia the physical breaks are unusually prominent, both above and
below, over its entire extent in the upper Mississippi valley. What has
just been said of the upper member of the series is equally true of the
one immediately underlying, though in a less marked degree and over
only a part of its superficial occurrence. Between the lower two groups
the physical continuity is scarcely broken, and the separation is chiefly
upon faunal and lithological grounds.

Lithologieally the upper two members of the Mississippian are more
alike than any of the others: yet as a rule they are readily distinguish-
able everywhere. The Osage group of limestones is over all its range
encrinital, and stands out in marked contrast from the other three sec-
tions ; while the lower subdivision is very different again, both in the
calcareous and the argillaceous portions.

X I. I '.i i i Rkoi Si* \ h., Vol.. ::. 1801.

300 C. K. KEYES — THK PRINCIPAL MISSISSIPPIAN SECTION*.

In regard to the minor subdivisions of the four groups above men-
tioned much might In- said. The several sectional names proposed at
various times have had wide value- and, moreover, have been applied
rather loosely.

In the Kaskaskia the upper shales and the lower limestones of Chester.
Illinois, have been differentiated, while the Aux Vases sandstone has
been placed at the base of the group, provisionally. It has not had. as
vet, sufficient study over its entire exposure to satisfactorily consider its
relationships in all its phases. Certain it is, however, that when the con-
tinental area north of the present city of St. Louis was being subjected to
denudation prior to the deposition of the lower Coal Measures the great
^sandstone was laid down south of that point in the shallow littoral waters
of the interior sea.

The St. Louis group has been divided into three limestone. Of these
the Ste. Genevive has never come into general usage, and practically has
been forgotten. The St. Louis limestone itself has been widely recog-
nized, and in many places the lower portions have been correlated with
the Warsaw beds as developed at the mouth of the Dea Moines river.

The Osage group is now made to include all five of the hitherto recog-
nized beds, the Warsaw proper, the geode layer, the Keokuk, and the
upper and lower Burlington limestones.

The Kinderhook group is a three-fold division whose several members
are strongly contrasted and persistent over wide areas.

The history of the shore-line shifting of the great interior sea is a theme
for detailed elucidation. Much has already been done toward this end.
I>ut some further information is requisite before a satisfactory presenta-
tion of the subject can be made.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 301-330

TWO MONTANA COAL FIELDS ,

WALTER HARVEY WEED

ROCHESTER
PUBLISHED BY THE SOCIETY

June, 1892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 301-330 June 28, 1892

TWO MONTANA COAL FIELDS.

BY WALTER HARVEY WEED.

(Read before the Society December 30, 1891.)

CONTEXTS.

Page.

1. The Great Falls Coal Field 301

Introduction 301

Location and Extent of the Field 303

Configuration and Structure 304

The geological Column . . 305

Sections 305

The Carboniferous 3C8

The Jurassic 309

The Kootanie 309

The Dakota 310

Descriptive Geology 311

Sandcoul£e Basin 313

Structure 313

Sandcouli'e Coal Mines 316

Belt ( 'reck I'.asin and Mines 318

( >ther Parts of the I Jreat Falls Coal Field 322

Age of the ( rreat Falls Coal 322

2. Notes on the Rocky Fork Coal Field of Montana 324

Locat ii m and general Features 324

Extent of the Field 325

The ( !oal Measures 325

St ructure 325

hr. I Lodge Mines 320

Bear ( !reek Mines ::2S

A.ge of the Rocky Fork < !oal 329

/. THE CHEAT FALLS COAL FIELD.

I NTRODl « TION.

Near the rapidly growing city of Groat Falls, Montana, the Missouri
river emerges from the Belt mountains ami begins it< long eastward
course through the groat plains. The rapidly flowing stream soon com-

X I.I I'.i ii oi;..i.. Soc. Am., Vol ::. 1891. 01)

302

W. II. WEED — TWO MONTANA COAL FIELDS.

mences to cut through the nearly horizontal strata of the plains, and
near Great Falls plunges over a series of sandstone ledges in a succes-
sion of cataracts collectively known as the " Great falls of the Missouri.''
Below the falls the sandstones gradually pass beneath the dark carbona-
ceous shales so well exposed at Fort Benton, from which place they take
their name. These sandstones, with their interbedded shales, now known
as the Great Falls formation, have long been known to all geologists visit-
ing the region, but until recently failed to reveal any fossil remains and
were referred to the Dakota epoch, whenever mentioned, on account of
their inferior position to the well developed Fort Benton shales. Their
true age was first made known by Professor J. S. Newberry,* who identi-
fied a number of fossil plants from the Great Falls formation and found

Figure 1. — Sketch Map of Montana showing Location of Coal Fields.

The shaded zone extending from the headwaters of Musselshell river to the hit irnational
boundary includes the coal fields.

them to be species characteristic of the Kootanie rocks of the Canadian
geologists.

South of Great Falls, a few miles nearer the mountains, this formation
holds a thick seam of excellent bituminous coal, which is being exten-
sively mined at Sandcoulee and has been opened at a number of other
localities along the base of the mountains. The area underlain by coal
has been called the Great Falls coal field, and as these strata constitute
the only occurrence of the Kootanie rocks yet recognized in our territory
they possess a decided interest apart from their economic importance.

In prosecuting a study of the coal fields of Montana for the United
States Geological Survey, a visit was made to this held in the spring of

♦ School of Mines Quarterly, vol. viii, no. 4, July, 18S7, p. 327.

RESULTS OF RECENT RESEARCHES. 303

1891, and the tacts then observed are believed to be of sufficient interest
to present to the Society. They prove —

1. The identity of the fossiliferous strata near Great Falls with those
of the coal field ;

2. The position of the formation relative to the Carboniferous and to
the Fort Benton rocks, as established b}r a carefully measured detail sec-
tion ;

3. The occurrence of fresh-water shells above the coal;

4. The absence of recognizable Dakota strata ;

5. The termination of the Carboniferous deposits in a scries of shales
and impure limestones, stratigraphically and lithologically the equivalent
of the Myacites beds of the Jura-Trias of southern Montana, but carrying
lower Carboniferous (Spergen hill) fossils.

The eastern portion of the field was examined by the geologists of the
Northern Transcontinental Survey in 1880. Professor W. M. Davis, in
studying the relation of the coal to the older rocks, measured two sections
from the Cambrian to the horizon of the coal, of which detailed notes are
not given. A graphic representation of these sections was published,
with lists of fossils determined and an interesting account of the adjacent
mountain region, in the reports of the Tenth census.*

In the investigation of the coals from an economic standpoint for the
same survey, the coal seam was traced by G. H. Eld.red.ge from the Judith
basin to Belt creek, and sections of the seam, wherever opened at that
time, will be found in his report.f Somewhat later Professor J. S. New-
berry made an examination for the Great Northern railway of that part
of the field now worked, and mentioned the general relations of the coal
rocks to the underlying Paleozoic terranes, in a paper on the geology
and botany of the country bordering the Northern Pacific railroad. J

Location' and Extent of the Field.

The Great Falls coal field, as already indicated, is situated at the base
of the Rocky mountains in central Montana., and takes its name from
the town to which it is tributary, [ts proximity to Helena, the state
capital, and to the great mining center Butte, with the increasing market
afforded by the smelters and other industries of ( itvut Falls itself, makes
the Held of the first importance in the future developmenl of Montana.

Coal has been found in the ECootanie rocks all along the base of the
mountains from the vicinity of fort Shaw eastward to the Judith basin.

♦ Tenth Census: Mining industries, vol. sv, Washington, 1886, p 69T.
t [bid., p. 739.
Innals oi the V \ \.ce I imy ofS siences, vol. iii, 1831, no. 8.

304 W. H. WEED — TWO MONTANA COAL FIELDS.

The seam has been opened at several places, and desultory working for
the local supply has been attempted on St. Johns creek, west of the Mis-
souri, and on Bird creek, Hound creek, Smith river, Dry Arrow creek, Wil-
low creek, and Sage creek. The more extensive workings of Belt creek are
sufficient to prove the value of the seam ; the mines at Sandcoulee have
an average daily output of 1,300 tons. It will he seen from the localities
cited that the field embraces a strip of country a few miles in width, but
extending along the base of the mountains for 125 miles, its extreme
limits being yet undetermined (see figure 1).

Configuration and Structure.

Throughout its entire extent the coal field is an open, grassy plateau
or prairie country, but rarely presenting low buttes or eminences left
by the erosion of higher strata, and cut by numerous drainages whose
coulees show sections of the rocks. To the southward the Belt moun-
tains form a rugged range whose higher slopes are dark with a heavy
growth of pines, the lower slopes presenting that park-like character
that forms one of the chief charms of Rocky mountain scenery. The
plateaus of the coal field extend northward, forming the western limit of
the great plains. In the center of the field, Belt creek has cut a narrow
valley whose groves of cottonwood and alders are in pleasant contrast to
the monotonous grasslands of the plateaus. Belt butte, a conical hill of
horizontal shales and sandstones, forms a conspicuous landmark, the
girdle of sandrock about its slopes giving it the name. To the eastward
the Highwood mountains break the continuity of the plains, rising
abruptly as an isolated cluster of picturesque peaks. The drainage of
the coal field, at least that part of it winch was visited, i- peculiar: The
level plateaus are trenched by narrow coulees, which are frequently
partially tilled with drift and are now occupied by streams of relatively
small size, streams that even in flood are not proportionate to the valleys
they occupy. The evidence seems to show that a period of depression,
when the plateaus were cut, was followed by a short time of relatively
high elevation accompanying the advance of local glaciers and a vigorous
drainage, which was followed in turn by the present period of scanty
precipitation.

The abundance of glacial drift on the plateaus was noted by Professor
Newberry. It is conspicuous when the glacial gravels till pre-existing
hollows and drainage channels, but on the mesas forms hut a thin and
widely spread mantle in which the bowlders are seldom of large size.
The material points to local origin of the drift, coming from the Little
Belt range. In the coal field proper no true moraines were observed.

RELATION OP en A I, ROCKS TO THE PALEOZOIC. 305

The gently inclined strata of the Great Falls coal field rest conformably
upon the Paleozoic terranes Hanking the granitic axis of the Belt moun-
tains, the easternmost range ol the Rocky mountain cordillera of this
locality. In these steeply upturned and folded Paleozoic strata the Cam-
brian, Silurian. Devonian and Carboniferous rocks have been recognized
by means of fossils. The massive white limestones of the Carboniferous
form the foothill country and pass beneath a series of gypsiferous red
sands and limy shales long thought to represent the Jura-Trias but re-
cently found to contain Carboniferous fossils, and these are in turn over-
lain by the sandstones and shale belts of the Great Falls formation. To
the northward these coal rocks are in turn covered by a heavy series of
strata, that pass into typical Fort Benton beds as identified by Professor
Newberry*

The Highwood mountains, whose proximity to the chains formed by
the uplifts of the eastern Cordillera would suggest a similar origin, arc
really a remnant of still higher Cretaceous beds, preserved during the
erosion of the surrounding country by a network of dikes and sheets
whose injection produced an induration of the strata that has left them
as a record of the sediments once covering this part of the plains. Toward
the cast and west this same general structure, with local modifications,
continues along the base of the Rocky mountains.

The geological Columx.

Sections. — The entire geological column, from Archean gneiss to the
shales of the Foil Benton group, is well exposed along the course of Belt
creek. This stream, rising in the Belt mountains, flows for several miles
westward along the strike of the Paleozoic limestones, and then turning
northward has cut the picturesque Sluice-box canyon through massive
Paleozoic beds, and reaches the more readily eroded clays ami sandstones
oftheMesozoic. At the lower end of Sluice-bos canyon, near Riceville, the
Paleozoic lime-tones dip deeply northward beneath the arenaceous beds
of the Gypsum series and the overlying gray shales. Starting at this
point, a continuous section was measured from the massive mountain
Limestones of the Carboniferous to the beds of supposed Fori Benton age
which overlie the coal-bearing strata and form licit butte. These meas-
urements are given in the natural order.

The following table shows, in considerable detail, the section (repre-
sented graphically in figure - I exposed in Bell butte:

♦ School ..i Min. - Quarterly, v.. I. viii, 1887, p. 327.

30G

W. II. WELD TWO MONTANA COAL FIELDS.

Figure 2. — Section at
Belt Butte.

22
21

20.

a 19.

Belt Butte Section.

Feet.

20. Sandstone, gray, slaty and hard, forming cap of the

butte ' 80

25. Slate, black 20

24. Limestone, white ami hard ; forms upper " belt "... 20
23. Sandstone, gray, irregularly bedded, breaks into

shelly detritus 90

Shale, black and earthy 100

Sandstone, unevenly and thinly bedded, usually light
earthy brown, holding carbonaceous Layers of 1 to 3
inches ; principal " belt " of the butte 50

Sandy shales, black and iron-stained bul hard and

shelly 20

Sandy shales, gray, more arenaceous than those be-
neath 40

Sandy shales, fissile and carrying \ proportion black

shale ; facies decidedly Benton 25

Shale, black " _ _ _ 75

Shale, sandy, gray, breaking into cubical hits 50

Limestone 10

No good exposures, hut slopes show debris of" white
vitreous quartzite resembling novaculite 75

Shale, black and earthy 10

Sandstone, marked by fucoidal rolls \

Shale, black and earthy, with one 6-inch band of sand-
stone 25

Sandstone 2

Shales, red and purple to purple-black, with rare layers

of harder sandy nick whose splinters strew slopes. 140

Sandstone, gray, weathering light brown; forms top
of a broad bench extending back to the base of Belt

butte 20

Gasteropod bed ; Goniabasis, Neritina, < 'orbula (?) .... 10
Sandstone, dense, lilac-colored, weathering purple-
brown 10

Series of thinly bedded sandstones and limestones"]
with alternating beds of shale, well exposed in
coulee, but not of sufficient interest to warrant
more detailed section, viz :

k. Xo exposure 21

/'. Sandstone, gray, cross-bedded )

'/. Shale * \ 10

//. Sandstone, buff, dense, uniform .... J

g. Sandy lilac-colored ledge 2

/'. Sandstone 5

e. Lilac-tinted freestone 20

</. Sandstone, fissile, gray, quartzose, very

hard and iron stained 17

c. Ledge of pink and lilac rock 30

//. Red and gray sandstones and shales. . . 45
a. Shale, sandy, but}', with red blotches. . . 10

15. Sandstone ledge, prominent stratum that throughout

the valley lies over coal 50

14. Coal 10

16.

160

1,092£

EXPOSURES ON BELT CREEK

307

The Belt butte section is supplemented by that exposed on Belt creek,
which comprises the following sequence (represented graphically in fig-
ure 3) :

Belt Greek Section.

Feet.

'-r.-j.tn,

14.
13.
12.
11.
10.
9.

( (verlying beds of Belt butte section 1,192|

Coal .' 10

Shaly sandstones 100

I'h.i i:i .;. Sed

/;■ // i 'reck.

Sandstone belt

Shales, limy

Sandstones, white

Limestone, gray and red, rust}'

Sandstone, white

Sandy shales, the lower 40 feet very ferruginous and

brown

s. | Sandstone, white, cross - bedded ; forms persistent

ledge

Sandstone, shaly and iron stained

Sandstone ; ledge forming bluff

7. Limestone, dense, light earthy gray

6. Conglomerate and sandstone, Jurassic fossils

5. Limestone, white, red earthy patches, Paleozoic

facies

4. Otter Creek shales; alternating gray, purple, green
and Mack shales and earthy limestones yielding
Carboniferous fossils; comprising —

x. Shales, dark gray and black alternating

with purple and green 45

w. Limestone 5

v. Shale, gray 30

tti Limestone, white 3

t. Shales, green and purple, limestone

lenses \ 25

s. Limestone, white, conchoidal fracture. 6

r. Shale, gray, green and red 8

q. Limestone, hard, dense, purplish-brown L}

p. Shale 1$

o. Limestone, pebbly, containing gaster-

opod shells 2

a. Shale, gray 3

in. Limestone, gray, weathering creamy,

usually brecciated 2

/. Shales, carrying Rhynehonella, etc 15

/,-. Limestone, irregularly bedded and of

varying lints of gray 5

j. Shale, black and earthy I

i. Limestone 15

h. Shale, earthy dark gray 8

g. Limestone, soft, crystalline •">

/. Shale, purple-gray < 8

i . Limesti »ne 3

d. Shale, black 16

c. < rypsum -■'

/>. Limestone conglomerate 2

n. Shale, dark gray 2

Black chert bell

Limestones and shales

< ij |isuin

Sai n Is, gray and while

150

25
5

6
10

215

I'll'

8
80

• »
• >

ll(

308

W. II. WEED — TWO MONTANA COAL FIELDS.

9 J

Red sands and gypsum layers made up as follows :

_/'. Sands, red 10

e. * rypsum, pure 5

d. .Sands, green-gray, shaly 35

c. ( rypsum, impure 11

b. Sands, reddish, soft, '■'> belts of gypsum,

3 to 6 inches 25

a. Sands, crumbling, red and white or
gray 25

Limestones, granular, earthy

Sandy clays, red and green mottled.

Feet.

1. Carboniferous limestones'"' 200

2,572^

The Carboniferous. — The series of red sandy gypsiferous beds overlying
the massive limestones of the Carboniferous and so closely resembling
the " Triassic " red beds were diligently searched for any traces of fossil
remains, but without success. This series (number 2 of the section) con-
sists of crumbling sands, soft and often incoherent, generally red in color,
though also white and gray, containing numerous seams or beds of
gypsum. The series corresponds in position and general characters to
the "red beds" which overlie the Carboniferous in Wyoming.

Overlying these gypsiferous red sands, there is commonly seen a series
of gray beds, also characterized in this section by layers of gypsum, one
of which is 3 feet in thickness. The gray shales and earthy limestones
of this series (number 3 of the tabular section) is capped by a belt of
black chert 8 feet thick, which was found at this horizon in several parts
of the field. The earthy limestones and shales resemble the Jurassic of
southern Montana, but are barren of fossils.

The series of alternating red or purple and gray shales and limestones
(number 4 of the section) are characterized by abundant fossil remains.
The thin beds of limestone, often but a few inches in thickness, contain
a number of small serpulas and the shales contain a variety of fossils.
These fossils have been seen by Dr. C. A. White and unhesitatingly
referred to the Carboniferous age. They have been identified by Mr. C. D.
Walcott, who reports the following species, viz, Retzia verneuiliana, Hall :
Rhynchonell'a osagensis, Swallow; Alhyris subtilita, Hall; Bellerophon car-
bonariios, Cox ; also lamellibranch shells belonging to the genera AUorisma,
Schizodus, and Aviculopecten ; as well as two species of Fenestella, shown on
thin fragments, and two species of coral of the genera Chsetetes and
Lophophyllum ( .'). Mr. Walcott reports that " the species appear to have
lived in a sea not favorable to their full growth or development."

The section made by Professor Davis a few miles farther eastward has
already been noted. I have examined the rocks at this locality and

♦ Characteristic Carboniferous fossils were found in the uppermost strata of number 1, establish"
ing its age beyond anv doubt.

MINGLING OF MESOZOIC AND PALEOZOIC PACIKS. 300

found a close correspondence with the section made by myself on Belt
creek. Fossils collected by Davis from these same shales, supposed by
him when in the field to be Jurassic, were reported to be Spergen hill
types by Professor Whitfield; this places them in the lower Carbonifer-
ous. The list given by Professor Whitfield is as follows :

Rhynchonella mutata, H. Terebratula turgida.

Proiluct i is tenuicostdtus, H. Allorisma, sp.?

Athyris trinucleata, H. IAngula, sp. ?

Eumevria verneuiliana. Stictopora, sp.?

These species and those enumerated above do not include a single
characteristic Jurassic type. Notwithstanding the wide range of many
of the species, and in general of the molluscan fauna so abundant in the
Carboniferous, rendering such paleontologic evidence by itself of little
value in determining exact horizons, it is noteworthy that fossils charac-
teristic of the lower Carboniferous should be found in beds formed during
the very close of the Carboniferous period. It should be noted in this
connection that fossils from a very much lower horizon in the section
made by Professor Davis are described by Whitfield as upper Carbonif-
erous. The stratigraphic position and lithological character of the lime-
stones and shales from which the fossils collected by myself were obtained
correspond closely to those of the beds found in southern Montana to
be characterized by an abundance of Jurassic fossils.* Such a decided
change in the upper part of the Carboniferous from that observed else-
where indicates a local modification of prevailing conditions and near-
lie--, (.f a shore line.

The Jurassic. — This shaly series is overlain by a bed that is character-
istic of the Jurassic throughout central Montana, in its lower portion it
is frequently a good crystalline limestone, passing gradually into a coarse
sandstone, frequently a conglomerate closely resembling the Dakota but
carrying Large numbers of Jurassic shells in both the sandy and limestone
portions of the bed (number 0 of the section).

The belt creek section gives a total thickness of 538 feet of beds be-
tween the white limestone of the Carboniferous and the Jurassic.

The Kootanie. — Overlying the Jurassic conglomerate bed (number 6 of
the section ) there is a series of rather thinly bedded stands! ones of vary-
ing degrees of coarseness and induration. Near the mountains these
rocks are ferruginous and bright ra] in color, but farther away from the
uplift they are white and contain intercalated beds of shale and ferrugi-
nous sands. A 5-foo1 bed of dense yellow sandstone, quite impure and
argillaceous, forms a recognizable division of this sandstone series. The

• Cf. W. H. Weed, Cinnabar and Bozeman Coal Fields: Bull. Geol. Soc. Am., vol. 2, 1801, pp

XI. II -I'.i 1 1 . Geoi . Soc. \m.. Voi . 8, L891,

310 W. II. WEED — TWO MONTANA COAL FIELDS.

coal occurs above tliis sandy belt, 1,479 feel above the mountain lime-
stone of the Carboniferous and 520 feet above the conglomerate carrying
Jurassic fossils.

No plant remains whatever have been found in the shales resting upon
the coal. Careful search was made at every opening of the seam for
trace.- of plants, but with the same lack of success that attended the efforts
of previous investigators. Slabs containing indeterminate shells of Unio
were once sent to Professor Newberry as coming from the roof of the
seam, but I found no fossils of any kind,

< >verlying the coal seam there is a prominent ledge of massive and dense
coarse sandstone capped by a series of rapidly alternating beds of lilac-
tinted or pink sandstones and red and purple shales. Like the same
beds at Great Falls, the sandstones form an excellent building stone.
This series is capped by an impure yellow limestone full of gasteropod
shells, which were forwarded to Dr. White for examination. His assist-
ant, Mr. T. W. Stanton, reports that these fossils consist of three forms of
fresh or brackish water types, viz, (1 ) Neritina, sp., resembling Neritina
(Neritella) nebrascensis, M. and H., from supposed Jurassic beds at the
head of Wind river, though the specimens (easts) are not well enough
preserved for positive identification; (2) Goniabasis {? . sp., some of the
more distinctly carinated forms very much resembling Goniabasis tenui-
carinatus, a Laramie species, though it is probable that all the elongate
gasteropods in this collection represent a single variable undescribed
species belonging to that section of Goniabasis which includes G. tenui-
carinata and 67. aultortuosa; and (3) some fragments of a small bivalve
that may belong to the genus ( 'orbula.

The beds from which the plant remains determined by Professor New-
berry were obtained are similar to those lying above the coal seam and
between it and this limestone, and they form the northern extension of
the same horizon.

The section above given represents the general characters of the Koo-
tanie formation throughout the field; briefly described, it is a series of
rapidly alternating sandstones and clay-shales, with few and thin beds of
impure limestone. Individual beds are inconstant, the heavy ledges of
firm sandstone passing laterally into arenaceous clays, and vice rrrsa. .

The Dalvla. — No definite recognition of the Dakota has been made,
and therefore only an arbitrary upper limit of the Kootanie rocks can
be assigned to the section on Belt creek. The gasteropod-bearing lime-
stone just alluded to is capped by a massive and rather coarse sandstone
bed 25 feet thick, which forms the top of the table-land 200 feet above
Belt creek. This is covered by a series of shale beds, black, purple and
red, carrying thin beds of sandy limestones and passing upward into a

ABSENCE OF DAKOTA CONGLOMERATE. 311

decidedly arenaceous shale that resembles the shales frequently found in
the Dakota of this region; but the typical Dakota conglomerate of more
southern localities is entirely wanting, nor is there any distinct sand-
stone zone of sufficient importance to replace it. The section of 780 feet
to the top of Belt butte shows a series of black carbonaceous shales with
sandy and flaggy shales and thin beds of sandstone. Number _!l of the
section is a bed of massive, coarse sandrock, 50 feet thick, that forms the
"belt" about the butte, and number "24 is a white and hard limestone
that forms the upper belt or crown. The top rock is a gray sandstone
underlain by black carbonaceous shales. Careful search was made for
fossils, but nothing whatever could lie found.

As noted farther on in this paper, the coal semi passes under the creek
(at the mouth of Little Belt creek); and beyond this point to its con-
fluence with the Missouri, Belt creek cuts higher strata, the bluffs of the
Missouri at fort Benton belonging to the Fort Benton group.

Descriptive Geology.

As it was deemed quite important to establish the exact horizon of
the coal seam relative to the shales from which the leaf remains were
obtained, the beds were traced continuously by means of ledges exposed
along the Missouri river and the Avails of Sand coulee from black Eagle
falls to the coal mines at Sandcoulee and across the plateau from the
latter place to the mines of Belt creek.

At Black Eagle falls, the first of the series of cascades below the city
of Great Falls, the river bluff is about 150 feet high, exposing a good
natural section, the rocks of which were even better exposed in the cut-
tings made for the dam and for the foundations of the smelter on the
western side of the river. Arranged in tabular form, this section is as
follows :

Thickness
Hill top, on which the smelter chimney is erected. in feet-

21. Sandy shale, greenish 20

•_'(). Sandy shale, red and purple 15

in. Sa nil nick Ledge, fissile, m 4 prominent 5

IS. ( 'lay ami red shale 15

17. ( 'lay and sands, green and gray ;>>

Hi. ( lay, red and Leafy shale 5

L5. I ronstone forming caps to sandstone pillars 1

II. Sandstone; crumbling, weathering into pillars and buttes; this i> hut a

lens of sandrock in a clay scries LO-30

L3. Clays L0

L2. Sandstone ledge ; forms top of river bluff 25 30

II. Clay-shales, red and gray on weathered slopes, blue-gray in fresh ex-
posures 50

312 W. H. WEED — TWO MONTANA COAL FIELDS.

Thickness
in feet.

10. Sandstone ledge, gray and hard 2

9. Shales, gray or red 15-20

8. < irav sandstone 5

7. Limestone, decomposed, brown, splintery 2\

6. Shale, easily crumbled, green-gray 5

5. Sandstone, passing into shales at base 7

4. Shale and shaly sandstone, rotten, red-brown 9

.'!. Sandstone, massive ledge, forming fall of river 7

2. Flagstone, purple and lilac sandrock 12

1. Sandstone, massive, square block jointing 5

At the top of the section there is a sandy series (numbers 10-21) whose
erosion has formed most picturesque and brilliantly colored miniature
badlands. The beds change rapidly horizontally, passing into the lilac
sandstone (freestones) and clay-shales, the sandstone being an excellent
building material and easily quarried and much used. The clay-shales
interbedded with them hold the beautiful ferns identified by Professor
Newberry. These beds rest on a massive layer of buff sandrock con-
taining thin seams of lignite which, traced southward, is found to corre-
spond to the sandrock above the coal seam. This ledge illustrates the
difficulty of following a particular ledge of sandstone any considerable
distance, for it passes into clays and sands a few miles to the northward,
and is not a decidedly recognizable horizon at the south. Beneath this
sandrock, forming the top of the bluff, there is an alternating series of
clay-shales and sands, which are blue and gray where freshly cut for the
walls of the new smelter, but generally weather reddish or brown ; beneath
these shales, a ledge of soft granular sandstone caps a series of soft clay-
shales, resting upon the lilac-colored or pinkish sandstones forming the
falls — rocks that pass laterally into red clays half a mile down stream.

Traced southward, the upper members of the section are seen to form
the slopes about the city of Great Falls, the city dam being built on a
sandstone ledge corresponding to number 12 of the foregoing section.
South of the city the eastern bank of the Missouri shows exposures of red
clays with freestones and shales that are quarried at a number of points
between the city and Sandcoulee. At the mouth of the valley known
as Sand coulee, where the creek empties into the Missouri, a ledge of
white quartzose sandstone outcrops on the slope some 25 feet above the
river; it corresponds in horizon to that on which the city is built, and
forms a readily traceable ledge, extending up the coulee to the coal mine-.
It is capped by rather thinly bedded, square-jointed, lilac or pinkish
sandstones and alternating slate beds, which form excellent building-
stone. Following these beds upthe coulee the coal seam does not appear
until reaching a branch of Sand coulee known as Straight coulee, on

STRATIGRAPHY OX SAND COULEE.

313

which the Sandcoulee mines open, where the coal appears beneath the
massive sandstone ledge traced up the valley. At the mines it is about
20 feet thick and is a hard white quartz rock. The coulee slopes are
generally drift-covered, but a natural section is exposed where the wagon
road ascends the plateau, showing the following beds :

Feet

Sandstone 30

Shaly beds 25

Sandstone, square-jointed, buff; really a pebbly grit 3

Shaly beds, purple and red, crumbling (?)

Shaly beds, pebbly, gray and green, crumbling (?)

Sandstone ledge, same as that over coal ; no coal seen.

Where the wagon road descends into Straight coulee, near the coal
banks, the following strata are exposed :

Feel

y,j.':

Sandstone, forming summit of plateau.

Sandstone and sandy shales, red and gray, alternating beds. 50
Shales and clays, red and buff 50 to 75

Sandstone, forming bed above coal seam 20

dial seam 12

Figure 4. — Section
on Sand Coulee.

The plateau summits are quite gently undulating surfaces, well grassed
but bare of trees or shrubs, with a covering of glacial drift not of sufficient
thickness to produce a, marked drift topography but filling preglacial hol-
lows. Bowldersare not common but include a variety of rocks granite,
limestone, etc — found in the Belt mountains.

Sandcoulee Basin.

Structure. — That portion of the Great Falls coal field adjacenl to the
Sandcoulee mines can best be alluded to as the Sandcoulee basin. In
prospecting the field it has been found thai the seam thins out toward
both the north and the south from the mines. Toward the west the seam
splits into two beds, separated by 25 feet of shale, but probably is con-
tinuous, if not workable, to the bluff's of Smith river, though the prospect-
ing indicates a shallow basin.

314

W. II. WEED — TWO MONTANA COAL FIELDS.

The following section represents the strata exposed on McGriffin
coulee, a branch of Sand coulee, near the coal mines:

25 Laminated hard brown sandstone.

6 Massive coarse mottled sandstone.

\2 Fine grained white massive sandstone.

io Fine grained brown massive sandstone.

id Shales, dark red, holding nodules.

Calcareous conglomerate.

Red shales, holding*arenaceous limestone nodules.

Sandstone, massive, fine grained, white.

Limestones, very arenaceous, light purple or red, with elay and calcite.

Alternating purple and red clays and arenaceous limestone.

Arenaceous limestone, massive, light red.

Arenaceous limestone in purple shales.

zo Red and purple shales.

13 Dark purple shales.

20 Massive freestone or sandstone.

„ Coal seam.

i Fire-clay.

s Gray and yellow7 shales.

iZ Soft ferruginous laminated sandstones.

i'J? e Mottled gray laminated sandstones.

t?*v/s//y//y'/-/y\ * Stratum of impure iron ore.

io Soft shales and clays, mostly gray.

, Impure iron ore.

6 Soft shales, very ferruginous.

■3 Soft gray sandstone.

' - * 6 Conglomerate.

is Sandstones, massive above, laminated at base,
io Carboniferous (?) limestone.

Figure 5.— Section at
Sandcoulee.

The only working within this basin and the chief mine of the entire
field is thai of the Sandcoulee Coal company. In the prospecting of the
basin by this company several drill-holes were driven, which furnish
complete sections of the strata above the coal seam. By the kindness of
President ( Jocker* 1 have heen placed in possession of the records of these
drill-holes, sections of which are presented in the accompanying table.
Though sections of precisely identical strata, they differ somewhat in
detail and show the local changes of particular strata. The three borings,
designated respectively as numbers 1. 2 and 3, lie in a north-and -south
line at intervals of half a mile.

*I am under obligation to him and to Superintendent Burrill for many courtesies and for
valuable information.

INCONSTANT STRATIGRAPHY AT SANI>('< H'LEE.

315

Diamond Drill Records <ii Sandcoidte.

Fnii'KK 11. — Strtioiis r, rraltt! hi/ Drilling at Snnilcmih'r.

Number 1.

Soil l'G"

[ronroek 6' 6"

Red shale .7

Sandrock 14' Soil

Ni^icer '2.

1' 6"

Number 3.
Soil

... 2'

Sandstone

Red shale '.

Yellow sandstone

... 10'

Pink shale

Wl ite sandn >ck

... 20'

Hard yellow sandrock....

... 5'

V-1 ',-Y lshA&\e, X% Li-i!tsl'ule ?' Light yellow sandrock.

Yellow sandstone / Sandrock vw -

1./

Black slate ami nmil 41'

Black slate

I tray and black slate

and "lays 11

Blue clays 18

2lO

Clay :;' i

Sandstone 1' |

Black slate and mud .. 20*

Limestone 3'

< ream-coloi ed shale... l.'

4'_''

Bl -lay 11'

Sandstone 22'

I Hay-shale and mud. W I

Liglll -hale |(|' f

•jo'

Sandy yellow clay 15'

Limestone 7'

Sandy red shale :;'

< iray shale (" soapstone "). 32'

yellow claj i

Limestone i

Sandstone and congli

ate

slate, running into above...

18'

::.;' G

Sandstone la' Sandstone 15'

Sandstone I2'G"

Black slate and coal 2' |

I laj and slate 1'6" |

Dark slateandcoal i' i"
Slate r

Slate and COal 2' 7"

Coal

Coal 6' 8" i

Slate r .-/•

0' 10'' Coal O'll I

Black slate 3'

Clay i'i,

Slate

Clay..

r i

31 G W. II. WEED — TWO MONTANA COAL FIELDS.

Sandcoulee Coal Mines. — The Sandcoulee coal mines are twelve miles
from Great Falls by rail and six miles east of the Missouri river. Like
the rest of the eon 1 Held, the country about the mines is a rolling plateau,
locally cut by the numerous branch coulees tributary to Sand coulee.
The mines are opened in the banks of one of these tributaries called
Straight coulee. The coal lies beneath a sandstone ledge that generally
outcrops upon the coulee banks, the slopes above it being generally grass-
covered and showing no exposures. There is a slight dip of the beds to
the northward, affording easy drainage and haulage.

The property now being worked shows an excellent fuel coal that can
be economically mined and is near enough to the point of consumption
to avoid excessive freight charges. Unfortunately for the early reputa-
tion of the product, the working was begun in an area of "dead " coal.
Experience has shown that where tributary coulees have cut down the
overlying strata the coal has lost its virtue and is high in ash and low in
volatile carbon, and its physical constitution is such that it is of very
inferior quality. It was in such an area that the early working was done ;
and this, combined with the fact that in mining the entire seam, as was
formerly done, a large amount of slate got into the coal from the parting
above the lower bench (a parting that is now used as a floor in the rooms ),
led to unmerited prejudice against the coal from this none.

Throughout the workings at Sandcoulee the seam shows a consider-
able variation in thickness, the upper benches now worked being from
3i feet to 7 feet thick. The quality also varies with the proximity to the
surface of the overlying ground in the manner already stated, and appears
also to depend somewhat upon the thickness of the slate roof between
the coal and the overlying sandrock. For the first 1,000 feet from the main
entry the coal is " dead,'1 the gases having escaped through seams in the
sandstone roof; and the coal east of this entry is similarly affected.

The following average section of the seam shows its character:

Top coal 23-28 inches.

Parting :; "

Coal 10 "

Parting 1 "

Coal 24 "

Parting 6-8 "

Coal 24 "

Figure 7.— Section

of Sandcoulee

Coal Seam.

COMPOSITION OF THE COAL. 317

( )n account of the thick parting above the bottom bench the coal is not
mined except in driving entries. The top coal consists of an upper layer
of 10 to 15 inches of dull and quite hard coal called "anthracite," but
carrying quarter-inch streakings of bright coal. Below itthe coal is mixed,
dull and bright, down to the uppermost parting. The second bench is
a bright bituminous coal and, like the bench below, is an excellent fuel
but carries balls of pyrite that cause much annoyance in mining and
prevent the use of the coal for many purposes.

Samples representing the average quality of the different benches ©f
coal were collected and have been analyzed for me by Dr. Stokes, of the
chemical laboratory of the United States Geological Survey. The analy-
sis of the to}» coal shows —

H,<> 3.66

Volatile hydrocarbon 30.88

Fixed carbon 55.50

Ash 9.96

100.00

A sample of the coal from the middle of the seam shows a very large
amount of ash, and is evidently the cause of so much complaint that the
coal output is dirty. The analysis gave —

11,0 2.68

Volatile hydrocarbon 26.36

Fixed carbon 44.01!

Ash 20.04

100.00

A third sample, from the lower bench, shows a cleaner coal, low in ash
and higher in volatile combustible matter, possessing coking qualities
that lit it tor many uses for which the coals of the upper bench are not
available. This bottom coal should be economically mined and sepa-
rated with present methods of working. Under the present management
the Large amount of ash experienced in using this fuel must be charged
to the coal itself and not to dirt from the partings.

An examination of the'seam as exposed throughout the workings shows
that the thin partings in the upper portion are quite variable in thick-
ness ami position and are occasionally wholly absent. Their maximum
thickness is about 2 inches. The lower parting is always present and
can be counted upon as to both position and thickness. As a rule the
roof is good, there being from 6 to is inches of slate over the coal. When
this slate is but 6 inches thick it is dill i cult to keep the roof up. but when
it reaches 18 inches the roof is perfectly sale. Throughout the mine the
roof rolls in gentle undulations.

\ I.I I I ■ I'.i 1 1 . Okoi,. Soi . \ n„ V.'i . :',, 1891,

318 W. II. WEED — TWO MONTANA COAL FIELDS.

The floor of the newer workings is the thick parting of slate over the
bottom bench of coal. En driving the entries this lower coal is extracted.
and there is some 3 feet of slate between the coal and the underlying
sandrock. The floor rolls up and down a good deal but runs into regular
strata.

The none at present is worked by the pillar-and-room system. Two
main entries are run. with side entries driven at right angles to them.
The main entries are 24 feet wide, timbered where the roof slate is thin.
but usually having a line of pillars in the center only. The right-angle
entries are driven 12 feet wide at the roof and no timbering is necessary.
The usual Mi) feet of coal is left between the air entry and the main entries.
The rooms are 24 feet wide, with a 12-foot pillar, and cross-cuts every loo
feet : but where the coal-cutting machines are used the rooms are 50 feet
wide with a 15-foot pillar, and 20 feet between belts.

The miners are. as usual, paid by the amount of lump coal delivered,
weighed as it i> dumped over screens into box cars, an automatic scat-
terer being used for loading. The nut coal averages 15 per cent of the
output, and there i- lo per cent of slack. The nut coal meets with a
ready sale, and the slack- is hauled away by the Greal Northern railway
and used as ballast. The cost of ordinary outdoor labor is $2.50 per
day. The miners are paid at the rate of 81.00 per ton.

Belt Creek Basix and Mines.

As tin.- plateau summit between Sand coulee and Belt creek is drift-
covered, no continuous ledge can be traced; but the low inclination of
the beds and the exposures seen on Box Elder creek and it< tributaries
are sufficient to establish the identity of the coal strata of Beltcreek with
those of Sand coulee. The prominent features of the topography are
the flat table-lands which extend eastward to the slope- of the High-
wood mountains and southward to the uplands of the Belt range.
Natural section- of the strata are found in small drainage cuttings trench-
ing the plateau walls. These are sufficiently illustrated in the general
section already given, which was made here1.

The strata of the licit creek basin possess a gentle northerly dip with
an extremely gentle local anticlinal fold in the center of the basin-
The rocks of the coal measures are the same as those found along Sand
coulee. The coal lies beneath a cap-rock of hard quartzose sandstone
60 to 75 feet thick in the southern part of the basin, though hut 25 feet
thick at the Armington mines. It is a coarse gray, very massive sand-
stone, having a prominent outcrojj tinted pink by the wash from the
shales above. The slope- above this ledge are usually grassy and show

THE PRINCIPAL WORKINGS.

319

no expi >sures up to the summit of the table-land, 200 feet al >ove the valley
bottom at A.rmington ; but sections of the rocks forming the table are seen

in small lateral drainage cuttings.

The rocks beneath the coal are seldom exposed, as the seam is gener-
ally hut 50 feet or so above the creek. Where the beds are cut by the
railway line in the northern part of the basin the following rocks were
found exposed :

Sandstone.

ij'° Coal.

g^^^B

oo Sandstone, alternating with shale,

Limestone

Sandstone, thinly bedded, alternating with 10 to L3 foot belts of
shale.
"> I>ense limestone, brown and splintery.

Figure 8.— Section

near Belt Ci eek.

At Armington similar rocks are exposed near the railway bridge.

The largest opening is the Castner mine, which was formerly worked
to supply the Fort Benton demand. The main entry is some (500 feet
loni, of which 115 feet only is timbered. In the rooms, pillars and caps
are used to support the roof. The seam shows a total thickness of 12 feet,
the uppermost 3 feet being too slaty and dirty to work and showing but
12 inches of coal. The bottom bench shows 20 inches of clean coal that
is used for blacksmithing purpose-.

< mi the eastern side of Bell creek is the Millard claim. The section of
this seam is essentially the same as that of the Castner mine, as will be
seen by the diagram (figure 10). In the room now being worked theseam
shows the following section :

» Top coal; dull and hard, with bright streakings.

. slate, 4 inches.

• Coal : bright, bituminous, in part a coking coal.
Slate, :d to I inches.

Coal; coking, and a good forge coal.

Slaty coal ; dirty and sulphurous, L8 inches.
Sandstone.

I IG1 ii 'i Si I

in Belt Field.

;;-jo

W. II. WEED TWO MONTANA COAL FIELDS.

The coking coal is separated in mining and sold separately for Mack-
smiths' use. The second parting is not separated.

Examinations of the coal bed, made at the various openings of the
Belt basin and other parts of the Great Falls field, show the following-
sections :

Sections of Coal Seams of the Great Falls Field, Montana.

( lastner

mine.

Millard

mine.

Watson
mine.

Arming-
ton
mine.

Sand

Entry.

Room.

Coulee.

Sandrock

Slate 9"
Coal 28"

Slate

20"

6"-10"

12"-15"

4"
20"

10"

20"

10"-12"

6"- 8"

24"

26"
4"
9"
4"

18"

0
24//

12"-16"

6"- 8"

30"-36"

16"

21"

6"-10"

10"
3"- 4"

14"

Coal

1!)"

Slate parting ....
Coal

24"

Slate parting ....
Coal '.

6"- 8"

24"

Pa/Ung

Coal

Parting

Watson. Armington

Figure 10. — Sections of Coal Seams of the Great Falls Field.

Sand Coulee

The Belt creek mines are now worked only for household fuels, but
their consolidation has already been effected and their further develop-
ment is likely to be accomplished in the near future, now that railroad
facilities are afforded by the Neihart road.

The coal seam thins rapidly north and south of Belt. On the north il
is but 2 feet thick some two miles below Belt, and thins out near the
mouth of Little Belt creek, where the coal dips beneath the creek bed.
Toward the south the seam thins out and deteriorates in quality toward
Otter creek, and although it lias been found on Otter creek and opened
near Mann post-office (Otter), the seam is but ■'>'■ feet thick, the bottom
bench only being workable.

COMPOSITION OF COAL AND SKA MS. 321

Aii average sample of this coal taken by the writer and analyzed by
Dr. H. N. Stokes, of the United States Geological Survey laboratory,
shows the following composition :

H,0 3.05

Volatile hydrocarbon 41 .01

Fixed carbon 52.31

Ash 3.63

100.00

The roof here shows 10 inches of slate between the coal and the sand-
rock, and the roof rolls slightly, pinching the seam. The two partings
are always present, the upper one varying, the lower very constant. The
top coal is long grained down to the lowest 4 inches, which breaks into
dicey bits.

The Castner and Millard mines are in the center of the Belt basin.
About a mile north of the latter the Watson mine shows the seam to be
1 1 feet thick, the upper 3 feet 1 >ei i ig too dirty h > w< >rk. The section shows
the seam to be quite dirty and the coal, particularly the lower bench,
sulphurous. The roof is uniform and flat. The structure is as follows :

« Top coal.

• Slate ; very bard.'

i2-i« ( loal.

** Slate.

« Coal ; dirty.

Figure U.— Section at Wation Mine.

North of this mine the scam is not worth working, so far as shown by
the prospects yet driven.

South of Belt there are several openings at Armington, which show the
scam to be constant in character and to hold an excellent free coal. In
the old entry of the Armington mine, abandoned on account of a roll
of the seam, the following section of the coal was obtained 500 feet
under cover :

Sandrock.

Slate roof.
Top c< >al.

c-,o Slate.
,. Coal.
s" Slate.
" Coal.

Floor slate.

I Ml, i

6TI W. H. WEED TWO MONTANA COAL FIELDS.

Similar sections at the other openings show that the seam, though less
free from parting dirt than at Sandcoulee, is yet a valuable property.
The coal from many of the openings shows peacock tints and. like thai
of Sandcoulee, holds pyrite balls. The openings at this part of the field
show generally a firm sandrock roof over the coal.

Other Parts of the Great Falls Coal Field.

The Otter Creek coal has already been mentioned. The seam is too
thin to pay working,and whether it thickens to t be south in a continua-
tion of the Belt Creek basin, as present indications appear to point, can
be determined only by drill prospecting, as natural exposures are wanting.

Nothingis known of the eastern extension of the Great Falls field about
Dry Arrow, Sage and Willow creeks and -the Judith basin, save the notes
made by Eldridge for the Northern Transcontinental survey, though the
country has been prospected for several parties by local experts ; but the
-earn shows a workable thickness that will be of value when the Judith
basin is traversed by a railroad.

The western extension of the Great Falls Held shows a promising thick-
ness of coal at several points. The coal seam outcrops in the bluffs of
Smith river and at Hound creek, but the openings are of small extent
and are not worked at present. The coal seam is in a steep bluff some
."»oo feet above the river and shows a thickness of 5 feet '.' inches. Its
character is much like that of the Sandcoulee coal — a roof of hard slate
caps a dull coal, which lower down is streaked with bright coal. A thick
parting of sandy shale separates this upper bench from a good coking
coal below.

A mile and a half up Hound creek the seam is said to be but four feet
thick and to thin rapidly toward the south. To the northward the seam
thins out to four feet in the bluffs of Mings coulee, where it dips toward
the south, showing a shallow basin.

The seam is also reported to outcrop at the base of the mountains at
the head of Bird creek, near Chestnut, and but a few miles beyond.

As further exploration of the field is made in the search for special
grades of fuel better fitted for metallurgical purposes, there will be more
information available concerning the extent of the field and the geology
of the Kootanie formation.

Age of the Great Falls Coal.

To 1'rofessor J. S. Newberry belongs the honor of first establishing the
age of the Great Falls formation. The fossil plant remains upon which
this identification rests have been obtained from two localities : (1) a

THE GREAT FALLS FLORA. 323

railroad cutting 5 miles above the mouth of Sun river; and (2) a ravine
exposing the plant-bearing shales on the northern side of the .Missouri
opposite the city of Great Fads. At the first locality ferruginous concre-
tions were obtained containing well-preserved leaf impressions. The
following speeies have been reported from this locality by Professor
Newberry :

Zamites montana, Dawson. Podozamites latepennis, Heer.

Sequoia smittiana, Heer. S.fastegata (/). Heer.

Professor Newberry says, "These plants prove beyond question that
the Great Falls coal basin is of the same age with those that have been
described north ofthe boundary line by Dr. George M. Dawson in what he
has designated as the Kootanie series.'1 " The strata here dip h i the north ,
the coal passing under the barren sandstones and shales which form the
falls of the Missouri, and all the bedded rocks are concealed by drift as
far as observation has extended northward of the river." Detailed obser-
vations by the writer having confirmed this statement, the plant remains
found in the rocks north ofthe Missouri and opposite Great Falls afford
evidence of the Kootanie age ofthe coal measures, as well as proof of the
age ofthe barren strata.

A small collection of plant remains obtained for the writer by Mr. II.
S. Williams, of Great Falls, the discoverer ofthe first fossils found in the
formation, was submitted to Mr. F. H. Knowlton and by him sent to Pro-
lessor YV. M. Fontaine, together with a collection made by himself.
Professor Fontaine has written an interesting report upon these fossils,
which will appear in the proceedings of the United States National
Museum. The collections consist mainly of well preserved impressions
of ferns, many of them new species, besides a number previously iden-
tified from this locality by Professor Newberry. There are in addition a
few conifers and an equisetum.

The most interesting feature of Professor Newberry's latest paper was
the correlation of the Great Falls, Kootanie and Potomac formations, the
fossil floras of all three having many species in common. This is sus-
tained by the later collections mentioned above, though most of the species
identified by Professor Fontaine have not been identified in the Greal
Falls formation before.

.'. NOTES ON Till-: ROCKY FORK COAL FIELD OF MONTANA.
Location and general Features.

The Rocky Fork coal field lies at the foot of the Beartooth mountains
and south of Yellowstone river, Montana. The quality of coal, the thick-
ness and great number of the seams, with the unproved extent of the
field, make it of great importance notwithstanding the distance to the
larger centers of consumption. A branch line leaves the Northern Pacific
railway at Laurel, 13 miles west of Billings, and runs up Clarices fork of
the Yellowstone and its tributary, Rocky fork, to the mines and themin-
,ing town of Red Lodge.

The topography of the field is of a type common along the eastern base
of the mountains. Very gently sloping plains abutting sharply against
the steep rocky slopes of the mountains stretch out for many miles north-
ward. These plains are trenched by longitudinal drainages, the larger
streams from the mountains flowing in rather broad gravel-filled valleys.
the smaller streams beading in the plateau cutting down the benchland
slowly and exposing the tilted and eroded rocks which form the mesa.
Toward the south the mountains rise abruptly in rocky, buttressed slopes
to the crest of Ike Beartooth range, an unexplored glacier-crowned moun-
tain mass having the highest peaks in Montana. Toward the north the
table-land fades into the benchland and rolling hills of the Crow reser-
vation, a well watered country with broad alluvial bottom lands and well
grassed uplands, greedily coveted by the settlers of the surrounding coun-
try. The mountain slopes and valleys are wooded with a heavy growth
of pine timber, but the table-lands of the coal field are bare of trees and
shrubs, save along the water-courses, though well grassed and bright with
the colors of innumerable flowers.

The general features of the geology of the region are simple ; a section
shows a series of sandstones resting on the marine cretaceous in the val-
ley of the Yellowstone, dipping gently from 3° to 5° toward the moun-
tains but disturbed by gentle warping of the beds. These sandstones,
which near the mountains dip more steeply (averaging 15°) and carry
the coal seams, are faulted against the Paleozoic limestones which form
the mountain flanks : the latter weather in great combs and ledges, dip-
ping away from the mountains at high angles.

The benchlands which form so conspicuous a feature of the coal held
are covered by a thick mantling of more or less rounded drift, sometimes
to a depth of 160 feet. This gravel effectually conceals the truncate!

(324)

NUMBER OF COAL SEAMS. 325

edges of the underlying coal measure sandstones and makes it extremely
difficult to outline the extent of the field. •

A very brief but comprehensive account of the coal seams of this field
was published by J. E. Wolff* who visited the locality before the mines
were opened.

Extent of the Field.

Very little is thus far known of the extent of the Rocky Fork field.
Prospecting has been confined to the vicinity of the Red Lodge mines,
being chiefly done in the broken country to the eastward, where the deep
trenches of streams have exposed the coal seams. The coal has been
traced and found to be workable at least as far eastward as the Clarkes
fork bottom. Westward no prospecting whatever has been done, and
therefore the presence of the coal is not proved ; but the same geological
structure and the same rock series has been found by the writer to ex-
tend for many miles westward, and there is no reason to doubt the con-
tinuity of the coal measures in this direction, although prospecting with
drills will be necessary to prove the value of the land.

The southern boundary must perforce be the fault line that runs along
the base of the mountains ; the northern boundary of the field is at a
variable distance of 3 to 4 miles from this fault line, according to the dip
of the beds.

The Coal Measures.

Structure. — The coal seams occur interbedded with coarse gray and buff
sandstones and thin clayey shales, such as characterize the coal rocks of
the Bozeman field. Fossil leaf remains are found in these sandstones
and rather well preserved shells of Undo in the slates over the coal. The
total number of coal seams is not known, but nineteen have been ex-
amined, of which six have been mined at Red Lodge. Of the nineteen
seams examined, eleven show over six feet of coal.

About the town of Red Lodge the coal measures outcrop as heavy
sandstone ledges and shale belts on the eastern bluffs of the valley. The
prevailing dip is 15° southward or toward the mountains. The eroded
edges of the beds are covered by gravels known to be from 20 to 160 feet
thick in the vicinity of the town and forming the; surface of the level
benchlands in which the valley is cut. On the south the beds flatten out
toward the fault that brings the coal measures against the white lime-
stones of the Paleozoic. The coal rocks are cut by a dike of igneous
rock a mile above the town, a prominent ledge that was traced for sev-
eral miles to the eastward, trending southeasterly. The creek, issuing

♦ Tenth Census, vol. w, Washington, 1886, p. 755,

XLIV— Bl ii. < i i.i.i . Sor. Am., V.. i. :;. Iv.H.

320 W. H. WEED — TWO MONTANA COAL FIELDS.

from the mountains through a sharp cut in the upturned limestones
above the town, flows through the bowlder-tilled channel, whose well
grassed valley slopes show no exposures until the town is reached.

To the westward, crossing the broad benchland cut by shallow grassy
drains, the low ridge about 3 miles from the town forms the terminal
edge of a rising alluvial or wash slope or cone, the drift being wholly
local and mainly limestone from the neighboring mountain slopes.
About the head of a considerable drainageway that has cut down into the
soft sandstones overlying the coal measures, the strata are seen to dip
gently southward toward the fault. The rocks are mainly sandstones,
rather soft, and weathering into loose sands that form smooth grassy
slopes, with intercalated clayey shales and more rarely thin beds of lime-
stone. Westward the country is more broken and the slopes show simi-
lar southward-dipping beds, while toward the north the broad bench
lands continue for many miles. East of Red Lodge the branches of Bear
creek, a lateral tributary of Clarkes fork, have cut back the bench, form-
ing a deeph' gullied and hilly country, locally called " badlands." Here
the coal measures lie much flatter than at Red Lodge, and the coal seams
have been prospected at a great number of points. It is a promising part
of the field, but is dependent upon a railroad for its development.

Red Lodge Mines. — The only mines now operated in the Rocky Fork
field are those of the Rocky Fork Coal company at Red Lodge; to Dr.
Fox, the manager, and the other officers of this company, I am indebted
for many courtesies and much information. Six seams have been worked
three of which are not being mined at present, owing to their inferiority
to the others. The seams have an average thickness as follows : Number
i (most southerly seam mined), 6 to 7 feet ; number ii, 7 to 10 feet; num-
ber hi, 6 to 7 feet ; number iv. 12 to 13 feet; number v, 12 feet; number
vi, 5 feet.

Number vi is geologically highest of those worked, but 120 feet above
it there is a 3-foot scam of coal, and 600 feet farther up the creek an 18-
inch seam of coal. Below number vi there are nine seams outcropping
in the creek bluff, of which five show over 6 feet of coal, the best being
perhaps number viii. The farthest seam is about a mile below the mines
and is opened by a drift 100 feet long. The coal is 6 to 7 feet thick, strikes
east-and-west magnetic, and dips 10° southward. The rocks between
this seam and the mines are sandstones and gray shelly shales, barren
of fossils and strictly conformable. No outcrops occur below this seam.

Number i is no longer mined. It is the original " Yankee Jim " seam,
and is a good coal ; but the other seams are worked cleaner. The tunnel
was not safe to enter, owing to gas, so that no section was obtained.

Seam number ii is opened by an entry main 2,000 feet in length. Cross-
sections of this seam, made at the end of this entry, and of seam number

COMPOSITION OF COAL SEAMS.

327

iii, show the benches and partings represented in the first two columns
of the accompanying table and figure 13. Seam number ii dips south-
ward 15°. The upper bench of coal. 24 inches thick, is left up in the
rooms to form the roof. The sandstone lying above the seam occasion-
ally cuts out the slate over the coal. The thickness of coal is 7 feet 8
inches ; coal worked, 5 feet 2 inches. The roof of scam number ii is a
soapstone. This seam, though showing several thick benches, is not
worked on account of the partings. If worked in the future it will be
by the long-wall method.

N? 2.

Coal Seams of Red Lodge Mines.
N?3. N£4.

N?5.

Figure 13. — Coal Seams of Red Lodge Mines.

.X umber ii Section.
Sandstone roof.
Shite <;"

Slate 2"

Coal n"

Slate 2"

Coal 21"

Parting....:.... 2"

Coal is"

Dirl c"

l loal, clean, )
shackly, in"
fractured.. )

Parting I"

Coal i"

Fire-clay 6"

-' tndstone.

Number iii Section.

Coal

36"

Slate 2"

Coal 7"

Slate H"

Coal 5"

Slate 2"

• loal 6"

Clay and ) ..„
dirty coal J

Coal, clean ... 24"

Fire-clay... <5"-18"

Coal 48"

Slate.

Coal
Clay

Coal

Number iv Section

18"
3"

40"

Parting 1"

Coal 24"

Parting i"
Coal 18'*

30"

Parting
Parting

13"

a///
74

Coal

17"

Parting
Coal.....
Parting

14"

Coal

17"

Parting
< loal

Number v Section.

10"

4"
21"

Coal 6"

Coal

Parting 14"
Coal 4"

Clay

Parting 1"
Coal 2"

Coal

Parting 4"

(lav

Coal 12"

Coal

10"

1 '

I '/

Parting 1"
Coal 4"

Parting
Coal
Parting
Coal

Parting l"

Coal 30"

Fire-clay 8"

Coal 9"

Coal dirl 5"

Coal 24"

Dirty coal ... 10"

Coal with |
lenses of 30"
parting, j

328 W. H. WEED — TWO MONTANA COAL FIELDS.

The fourth and fifth seams show the structure indicated in the dia-
gram. The sections of seam number iv do not, of course, give the entire
width of the seam, but only the portion worked. The roof is a firm sand-
stone, so that only the main entry, 18 feet wide, is timbered, and the slope
the same. The seam is opened by a half mile of entry and a slope of
GOO feet. These workings show the seam to have a dip of 18° at outcrop
and 16° at the bottom of the slope, the roof being very constant. The
floor is a soft gray shale having a slight roll. The lower partings of the
seam are very constant, but the uppermost parting is quite variable in
thickness. The seam has a nearly uniform thickness of 12 feet, of which
20 inches is left to form the roof over the rooms. The roof of this seam
rolls considerably.

A 5-foot seam of coal lies between seams number iv and v, with 35 feet
of rock between it and number iv ; but the seam has too many partings
to be workable.

Number v is but little worked, the mine being abandoned on account
of the partings and the prevention of economical working by the bottom
coal. The roof rolls but very little, not so much as number iv. The coal
above the 30-inch bench is all one bench, or has but thin partings, of no
consequence farther in.

Seam number vi is 5 to 6 feet thick and shows a clean bench of coal
having only one parting of an inch in thickness about midway. The
coal is bright and breaks into prismatic masses with hackly fracture.
The roof rolls in strong waves and the floor also rolls. No timbering is
done in the entries of seams numbers v and vi, but though the roof of
number vi is a hard sandstone it is crushing in the rooms and is held up
by timber cribs.

While the seams numbers i, iii and v are not mined at present, owing
to the greater profit of mining the other seams, they are valuable for
future supply.

The Rocky Fork Coal company holds 3,440 acres of property, being a
strip about two miles wide (the entire width of the outcropping seams of
the field) and some three miles long, comprising the high benchland and
broken country about the head of Bear creek, east of Rocky Fork creek.
To the eastward the seams flatten out to a dip of 5°, with low arching
of the beds.

Bear Creek Mine*. — In this eastward extension of the field the area
available for mining has a much -greater width, as the beds flatten out
gradually toward Clarkes fork. In general the trend of the field is toward
the southeast. Numerous locations have been made and short prospect
entries driven on the seams that outcrop in the sides of the gulches. The
most extensive working has been made by agents of Butte capitalists,

CONDITIONS OF MINING. 329

who opened a 7-foot seam of coal, but abandoned it after a year's work-
ing. Coal taken out of the old prospect entry near by, that has been ex-
posed for three years, is hard and firm.

Taggart's claim, 4,500 feet in altitude by aneroid, shows a dip of 1° to 2°
toward the south. A short entry shows the following section, which was
taken at the outcrop and does not, therefore, fairly represent the seam :

Solid sandrock

Decomposed brown clay 36"

Coal 24"

Lignite bone 42"

Coal, forming entry roof 12"

Bony, dirty coal 12"

Clean coal 4"

Slaty dirt parting 2o"

Coal, clean 23"

Carbonacious slate parting 5"

Coal 24"

This part of the field can be mined cheaply, owing to the flatness of
the seams ; but the narrow gulches give no dumping ground. The lack
of transportation is the only great obstacle to the rapid development of
the mine.

Near Clarkes fork the ridge shows a heavy outcrop of sandstone com-
posed of granitic grains and forming ridges 150 to 175 feet high, the beds
dipping southward 4°, and coal seams lying beneath the sandstones.
East of Clarkes fork the soft clays of the Tertiary (?) appear, the river
cutting through a low synclinal arch.

The continuity of the coal field toward the southeast is interrupted by
the river valley and the eroded basin of Grove creek, now a broad wash-
plain. At the head of this gravel plain the Cretaceous sandstones and
clays, carrying lignites, dip 5° toward the mountains, the summit being
about 5,320 feet in altitude, and the ledges abutting against a Carbonif-
erous conglomerate dipping northward 75° and underlain by massive
limestone cut into picturesque, castellated forms by the mountain tor-
rents. The fault line extends southeastward, so far as can be seen, at least
a couple of miles beyond here. From this point to the most westerly
spot visited, some eight miles in all, the structure is the same. East of
Clarkes fork, Pryer mountain shows beds dipping southward.

Age of the Rocky Four* Coat,.
Below seam number i there is some 60 feet of sandstone weathered

down to a slope, with a bold outcrop of massive sandstone some .",(> to 40
feet in thickness below it, This rock is coarse, formed of granite debris,

330 W. II. WEED TWO MONTANA COAL FIELDS.

and is cross-bedded and pitted. It shows poorly preserved leaf remains.
Fossil leaf remains occur in a Letter state of preservation in the sand-
stones between numbers iv and v, where they have been quarried for
building purposes. A collection made by the writer has been studied
by Mr. V. H. Knowlton, who reports the species to present a decidedly
Fort Union fades.

The remains of Unio obtained from the roof of scam number iv have
been examined by Dr. C. A. White, who reports them to belong to two
species, Unio senectas, White, and Unio dmifr, M. A* H. These species are
of too widespread occurrence in the fresh-water Cretaceous rocks to fix
any definite horizon.

In the lack of definite structural evidence of the age of the coal meas-
ures, we must therefore rely upon the plant remains. These are of Fort
Union types and belong to a flora quite distinct, so far as studied, from
that of the true Laramie, or that of the Livingston beds of the Bozeman
coal field farther westward.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 331-368, pls. 10-12

PALEOZOIC FORMATIONS OF SOUTHEASTERN MINNESOTA

C. W. HALL AND F. W. SARDESON

ROCHESTER

PUBLISHED BY THE SOCIETY

.I i \i:, L892

BULL. GtOL. SOC. AM.

VOL I. 891. PL. 10.

PROFILE
Trom Saint Cloud, Minnesota to Mason City, Iowa.

Horizontal distance 150 miles; Unit of elevation 200 feet

Saint Cloud

iz '

^j-,,..

too*

*N*V '. •'. •.-;

s- -

' '^v» •::•'•. •■

6 -i

»• ' N>»- • . •■ . ■

* -

' ' ^0- •'"••.•

2 -\

2 1

v -1

* -

► v k

r -

tOO).-

12 J

* 'ir'r .' . * ," „e ,'„ k '

Map anH Profile of South Eastern Minnesota.

"-r i nc

GEO, fMENT

COLUMBIA COLLEGE

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL.. 3, PP. 331-368, PLS. 10-12 JUNE 23, 1892

PALEOZOIC FORMATIONS OF SOUTHEASTERN MINNESOTA.

• BY C. \V. HALL AND F. W. SARDESON.

(Bnu I before the Society December 29, 1S91.)
CONTENTS.

Page

Introduction '.',:\2

Resume" of earlier Investigations 333

The upper Cambrian 335

The Potsdam Sandstone 335

The pre-Paleozoic Floor of the District 335

The basal Conglomerates of the Potsdam 336

Localities of the Potsdam 337

Structural ( lharacters 337

Lithologic Characters 338

( 'hcmieal Composition 339

Paleontologic ( lharacters 339

The Magnesian Scries 340

Subdivisions of earlier Writers 340

Localities of the Magnesian Scries .'14.'!

Structural Characters 34:5

Lithologic ( lharacters 345

Chemical Composition 347

Paleontologic Characters 348

The Lower Silurian 349

( llassification of the ' rroup 349

The Saint Peter Sandstone 350

Localities 350

St ructural ( lharacters 350

Lithologic ( lharacters 351

Paleontologic < lharacters 352

Physical Relations 353

The Trenton Limestones and Shales 356

Localities 356

Structural < lharacters 356

Lithologic ( lharacters 356

Chemical Composition 357

Paleontologic < lharacters :;",-v

The general Section •'•:,s

The Buff Limestone 360

The Blue Limestone 360

XLV— Bum.. Gkot,, Soc. Am., Vol. 3, 1891. 331)

332 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA.

Page

The Slictopovella Bed ::!'ii

The St'irfiijmra (or upper Blue) Bed 362

The Fucoid Bed 363

The Zygospira Bed 363

The Orthisina Bed 364

The Camarella Bed 364

The Lingulasma Bed •i,'»">

The Madurea Bed .' 365

The ( iincinnati Limestone and Shales 365

The Maquoketa Beds 365

Localities 365

Structural Characters 365

Lithologic Characters 366

Paleontologic ( lharacters 366

The Wykoff Beds 366

Localities 366

Structural Characters 366

Paleontologic Characters 366

The Devonian 367

Localities 367

Structural Characters 367

Lithologic Characters .'!'J7

Paleontology ; »< »~

Summary of the Stratigraphy 368

Introduction.

The rocks described in the following pages occupy the entire area of
southeastern Minnesota, some 13, 200 square miles in extent. They
stretch eastward from a straight line between Mankato and Hinckley to
the state of Wisconsin, and from Chengwatona southward to Iowa.

The periods of geologic time represented by these formations are three,
viz. Cambrian, Silurian and Devonian. That portion of the Cambrian
exhibited is the upper, of the Silurian the lower, and of the Devonian
so thin a layer is present and so few fossils occur in it that we cannot
assign the rocks to any division of that group, but suppose them to lie-
long near the middle.

These Paleozoic rocks are underlain by the Archean and Algonkian,
and lie beneath patches of Cretaceous and a covering of Quaternary
debris save in that extreme southeastern corner included within the
" driftless area " of Chamberlin *

*See map and description in "The Driftless Area," et ■. by T. ('. Chamberlin and H. D. Salisbury,
Bth Ann. Rep. U. S. Geol. Surrey, 1885, pp. 205-322.

THE FORMATIONS DESCRIBED. 333

The lowest rocks considered in the following pages arc referred to those
now grouped as upper Cambrian. They will be discussed under two
divisions, as follows :

•2. The Magnesian series = the Lower Magnesian limestones of Owen;

1. The Potsdam sandstone = the Lower sandstones of Owen.

The next higher group described is that commonly referred to the
Lower Silurian, including —

5. The Cincinnati ;

4. The Trenton ;

:!. The Saint Peter.

The highest rocks of the region described belong to the Devonian.

Throughout the paper the rocks will be described in ascending order.

Resume of earlier Investigations.

This portion of Minnesota has been a favorite excursion ground for
the explorers of the Northwest since the time of Jonathan Carver. It
was he who first attempted any description of the rocks of this area.
He mentions that at the mouth of the Saint Peter river there exists a
bed of sandstone whose color is as white as the driven snow* Later
Lieutenant Pike,f Major Long,| and Featherstonhaugh § visited the falls
of Saint Anthony and many other places of geologic interest. The last-
named writer was the first commissioned geologist who ever visited
Minnesota, and while the compiler for Long's expedition made a section
of the strata at Fort Snelling. Lieutenant Allen || described the bluffs of
the lower Saint Croix from Stillwater to point Douglas, and J. N. Nicol-
let *[ published many desultory notes on this region which were, how-
ever, chiefly geographic.

In the summer of 1839 David Dale Owen, of Indiana, received a com-
mission from the secretary of the United States Treasury "as the prin-
cipal auent to explore the mineral lands of the United States." His
instructions directed him "to proceed to Iowa and undertake an explora-

*Travels through the interior parts of North America in the yours 1766, '67 and '68 : J. Carver,
Esq., hoi, lin, ivT'.i, ]>. 59.

f Pike, .Major L. M. i An i ouni of expeditions to the sources of the Mississippi and through the

western parts of Louisiana, etc. Performed by order of the government of the United States during
tin- years 1805, '6 ami '7. [Uustrated by maps ami charts. Philadelphia, 1810.

I Narrative of an expedition to the source of Sain I Peters river, Lake Winnepeek, Lake of the
Woods.etc. Performed in the year 1823 * * '■■■ under the command of Stephen EI. Long, 1 . S-
T. E. William 11. Keating, J vols., London, 1825 (see p. 320).

gA canoe voyage up the Minnay Sotor, by G. W. Featherstonl gh, -J \<>K, London, 1847 (see

chaps, xwi-xxxvii. inclusive).

American State Papers, vol. v, Military Affairs : Map and Journal of Lieut. .1. Allen, in charge of
escort i npanying Schoolcraft's expedition t.. tin- sources of the Mississippi, pp. 312-344.

' Report intended to illustrate a map of tin' hydrographical basin "t the upper Mississippi river,
made by J. X. Nicollet February 16, 1841 (Senate Document 237, 26th ( ongn ss, 2d session).

334 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA.

tion of all the lands in the Mineral Point and Galena districts. ':: * *
together with all the surveyed lands in the Dubuque district." ' He was
farther directed, as he says, "to select specimens of all the minerals of
much value and to forward these to Washington city, as such a collection
was deemed important to illustrate my official report, -;: :;: :;: and
also interesting as forming the nucleus for a national cabinet."*

This line observer and enthusiastic geologist, who labored so untiringly
to extend our knowledge of the geology of the northwestern states, en-
tered upon his labors in the upper Mississippi river valley. He lived
long enough to see his work develop into at least three state surveys,
several surveys under the United States government, and a magnificent
national museum at Washington.

In the report cited,f Dr. Owen distinguished for the Northwest—

5. The recent deposits :

4. The Tertiary strata :

3. The Secondary strata;

2. The Primary fossiliferous strata :

1. Granite and other crystalline rocks.

Owen's more systematic work, however, was done on his return to this
region in 1848 for more detailed geologic explorations. In his report
of this work he distinguished the Paleozoic series — "The Primary fossil-
iferous strata '' — in ascending order! as :

5. The Carboniferous limestones and coal fields of Iowa and Missouri ;

4. The Cedar limestones (contemporary with the Devonian formation
of the English geologists) ;

3. The Upper Magnesian limestones ;

2. The Lower Magnesian limestones ;

1. The Lower sandstones (the lowest protozoic strata I.

The opinion was expressed that the Lower sandstones extend beneath
the drift of the lake Superior. country. Another opinion expressed by
Dr. Owen must not here be omitted, since it was so ac< urate a prophecy :
"There can now be little doubt that the whole mining region of the
Mineral Point and Dubuque districts of Wisconsin and Iowa is based
upon a syenitic and granitic platform, which would in all probability be
reached by penetrating to the depth of from 2,000 to 4,000 feet "^ The
artesian and other deep wells at La Crosse. Prairie du Chien, Mason ( ity.
Lansing and other points show the granitic floor to that distance south-
ward to be less than 1,500 feet.jj

* Senate Document 407, 28th Cong., 1st session, 1814, pp. 12, 13.

t [bid., p. 15.

JReportol > Geological Survey of Wisconsin, Iowa ami Minnesota. Philadelphia, Lippineott,

a ( ... 1852: Introduction, p. xix.

glbid., p. 62.

|] Bull. Minn. Acad. Nat. Sci., vol. iii, no. 1, 1889, p. 135.

WOliK OF THE MINNESOTA SURVEY. 33.")

In Marchf 1872, under enactment of the legislature, the regents of the
university of Minnesota were placed in charge of a geologic and natural
history survey of the state. In that same year a state geologist was ap-
pointed, who has been working under somewhat limited appropriations
to the present time. In order the more completely to carry out the
intent of the law. the regents also appointed in 1888 a state zoologist, and
in 1890 a state botanist. The publications of this survey thus far have
been a series of annual reports, the nineteenth of which is now in press)
several special bulletins ; and two volumes of the final report, all of which
are geologic except bulletins 3 and 4 and some special papers in the
annual reports. Much is contained in the annual and final reports by
X. II. W'inchell, state geologist, and Warren Upham and M. W. Harring-
ton, assistants, on the geology of the portion of the state discussed by the
writers. Wherever use is made of this material reference will be made.

Finally. Warren Upham placed in the hands of one of the authors a
manuscript which contained ;i syllabus of his observations in this por-
tion of Minnesota up to the time of its preparation. It bore the date of
May 5, 1883.

The upper Cambrian.
the potsdam sandstone.

Tin pre-Paleozoic Floor of tin District. — The formations under consid-
eration were laid down upon a floor of Archean and Algonkian rocks.
This floor has been found below the Potsdam sandstone at Minneapolis,
Stillwater and Brownsdale, and without doubt much if not all of the
territory lying between those places and westward is underlain by the
granitic and gneissic rocks. Probably three divisions of the Algonkian
are represented. In the northeastern corner the Keweenawan diabases
pass under the sandstones and shales around Taylors Falls and have been
traced to Stillwater, where they lie 717 feet below the surface;- toward
the north and northwest the schists and associated eruptive granites dis-
appear beneath the feldspathic conglomerates of the Snake river; and
along the western side of the area the quartzites and arenaceous shales
of the red quartzite formation extend from Nicollet county southwestward
into [owa and South Dakota and were regarded as Huronian by James
Hall f and Dr. C, A. White;!; :tm' subsequently by the Wisconsin geol-
ogists || and the members of the lake Superior division of the United
Stat.- ( reological Survey.§

* A. D. Meeds, Bull. Minn Acad Nat. Sci , vol. iii, no 2, 1891, p. 274.
TTrans. Am. Philoa Soe . ue« ser., \"i \iii. L866, p, 329.
i leologj ••! towa, vol. i, 1870, p. 171.
Geology <>r Wisconsin, vol. iv, 1873 78, p. 575.
g Irving and Van Hise, Bull. U S. Geol. Survey, no. 8, 1884, pp. 15, 34; C.W.Hall, Bull. Minn. Acad.
Nat. Sci., vol. iii, no. ^, 1891, p. 248.

336 HALL AND SARDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

The basal Conglomerates of the Potsdam,. — Everywhere so far as the basal
beds of the lower sandstone, or Potsdam as it is generally called (follow-
ing the suggestion of Professor James Hall in 1843)* have been seen
they are strongly conglomeratic. The conditions prevailing in the for-
mation of such basal conglomerates have been pointed put by Irving,f
and indeed such beds are precisely what should be expected under the
conditions actually obtaining in the northwest at that time: material
broken from sea-cliffs and knocked about on the beach of a slowly sink-
ing land area.

At Minneopa the boring of a deep well in 1888 showed a conglomerate
lying between 575 feet and 800 feet below the surface. It was made up
of well rounded pebbles of a vitreous quartzite, some of them very large.
and many from one to three inches in diameter were thrown out during
the boring. They were bound together by a fine red or reddish-yellow
cement, which comes out of the well as an exceedingly clayey mud. The
material of the pebbles is identical in every respect with the quartzites
occurring from Courtland through Watonwan and Cottonwood counties
into southwestern Minnesota and southeastern South Dakota. It is
vitreous, non-granular, of varying texture and red color. A thin section
shows the cementing material to be arranged crystallographically with
the cemented grains and as enlargements upon them precisely as Irving
and Van Hise % have pointed out for the quartzites of Redstone (Court-
land), the nearest area of these rocks to the Minneapolis well, and also
as shown in a slide from the quartzite of Cottonwood county, Minnesota.
The Minneopa well was sunk to the depth of 1,000 feet, but the record
below 800 feet was thoroughly unreliable. §

On Snake river two miles above Mora there lies a bed of horizontal,
cross-bedded conglomeratic sandstone. This exposure is less than three
miles from the Ann river knobs of hornblende biotite-granite. The
conglomerate has a cheerful light-pink color and is uneven in texture,
the largest pebbles reaching a diameter of two or more inches. Many
rounded pieces of feldspar are to be seen. The whole aspect of the rock
is that of a clastic worn directly from the granites lying in the neigh-
borhood. The pebbles are somewhat kaolinized, more so than are the
granites of central Minnesota at the present time, a fact suggesting thai
the great bulk of the erosion which these rocks have undergone has been
suffered since the beginning of Pleistocene time. Both Shumard || and

♦ Natural History of New York, pari iv. Geology, 1843, p. -jt.

fOn the classification of the early Cambrian and Pre-* lambrian formations, R. I>. [rving, Seventh,
An. Rep. U. S. Geol. Survey, 1886, p. 397.

JOn Secondary Enlargements of Mineral fragments in certain rocks: Bull. U. S. Geol. Survey
no. 8. 1884, p. 34.

j)Cf. Hull. Minn. Acad. Nat. Sci., vol. iii. no. 2, 1891, p. 250.
Owen'.- i ion logical Sur\ <-y of Wi.-., la. ami Minn.. 1852, pp, 524, 525.

CAMBKI AN CONGLOMERATES. 337

Upham* have observed the conglomeratic character of these deposits
along- Snake river.

Finally, at Taylors Falls in two or three places, one of which is near
the crossing of the Saint Paul and Duluth railway at the entrance to the
village and the carriage road running southward from the public school
building, lies a continuous belt of very coarse conglomerate. The length
of the exposure is twenty rods or more, and it is covered toward the
southwest by the drift material pushed over the edge of the river gorge
from the northwest, The same kind of a conglomerate, together with
great cracked cliffs of diabase, whose crevices are filled with fossiliferous
material, is to be seen on the Wisconsin side of the river at Saint Croix
falls. Another bed is in the banks of the river between Taylors Falls and
Osceola, Wisconsin. This conglomerate is made up of pebbles of diabase
like the rock constituting the high, massive cliffs which along both sides
of the river here form the picturesque " dalles " of the Saint Croix. They
are dark colored; frequent fine examples of concentric weathering are
seen, a peculiarity very common among the diabases of the lake Superior
region. Some of the pebbles are very small, while others are of tons'
weight, They are cemented together by a shaly magnesian sandsone
carrying numerous cavities lined with crystals of dolomite, alternating
with compact portions well filled with shells of Lingulepis pinnaeformis,
Owen; Obolella polita, Hall, etc. A typical locality of this conglomerate
is represented by plate 11, figure 2, which is a photomechanical repro-
duction of the photograph taken from the western side of the carriage
road entering Taylors Falls from the south.

Localities of the Potsdam. — In addition to the places just enumerated,
this sandstone can lie seen in strongly marked exposures along Saint
Croix river from Taylors Falls to Marine, and in many localities in
Winona. Houston and Fillmore counties along the bluffs of the Missis-
sippi and its tributaries, particularly Root river and Rollingstone creek.
In places tins eroded formation produces the most conspicuous feature
of the bluffs along the streams named. In the Minnesota river valley it
docs not appear as a surface formation, but it is reached in several
wells.

Structural ('huniftcr*. — The Potsdam sandstone appears to have been
laid down in a greal basin whose present rim is at the surface or beneath
the glacial drift from Watonwan county, in southern Minnesota, north-
easterly into Kanabec county, and from Chengwatona across the Saint
Croix at the Kettle river rapids into Wisconsin, where il rests againsl the
Huronian quartzites in Barron county and the gneisses and -ehists of
Archean and Algonkian age, past Chippewa Falls, Black River balls.

♦ The Geology of Minnesota, Final Report, vol. ii. L888, p. 021.

338 HALL AND SAUDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

Grand Rapids and Stevens Point,* On the southern borders, however,
the rim of the basin lies beneath other and subsequent formations. The
deepest known portion of this basin, is at Minneapolis, where granitic
rocks have been struck at 2,150 feet below the surface. The slope of its
bottom upward from this greatest depth is somewhat rapid toward the
northeast, where Keweenawan diabases appear at the surface within 35
miles, and the northwest, where granite quarries lie within 50 miles in
an air-line. Toward the south and southeast, however, the slope is more
gradual, as granitic rocks have been reached at La Crosse about 500 feet
below the Mississippi river.f

Throughout the entire thickness of this sandstone, which at Minneap-
olis is nearly 1,550 feet J and at La Crosse 375 feet, are shown the ordinary
structural variations of a great sandstone formation. In places a heavy
conglomeratic character is observed; again a decidedly shaly condition
prevails. While everywhere a stratified condition is seen, in some places
this is much more marked than in others. It varies directly with the
variation from the sandy to the shaly condition of this rock, being most
complete with the latter, and is brought out beautifully when the rock
is subjected to erosion or weathering. With the filling of this basin and
the more rapid accumulation of sediments in its deepest portion a very
level floor was formed at a quite uniform depth below the sea level, on
which were laid down the dolomites and dolomitic shales of the great
Lower Magnesian series of Owen, the Saint Lawrence, Magnesian and
Shakopee of Winchell and Upham, with their interbedded sandstones.

Lithologic Character*. — The conglomeratic, arenaceous, calcareous and
shaly phases of this formation have already been pointed out. In every
locality where its rocks have been observed a friable condition is con-
spicuous. Yet at Hokah, Dresbach, Dakota, Stockton and one or two
other places there is sufficient coherence or cementation to "encourage
quarrying; and, favorably for this business, the rock hardens on expo-
sure. Occasionally this coherence is secured b}^ the infiltration of a
cement of silica or through the compacting and partial alteration of the
rock itself, as at Dresbach and Dakota, but more usually through the
infiltration of calcium carbonate from the overlying dolomites and the
cementing together by it of the quartz grains. This condition is not so
common in these rocks as in those of one or two beds above them and
associated with the dolomites. It is not necessary here to give the anat-

*See General Geological Map of Wisconsin, 1881.

f From tin' records of the city engineer's office, La Crosse, through the courtesy of John James,
Esq.

I Bull. Minn. Acad. Nat. Sci., vol. iii, no. 1, L889, pp. 125-143. 'lie- classification there used is
essentially Warren Upham's as given in the manuscript cited (page 335). In this paper forma-
tions 11, 12, 13 and 14 (see pp. 134, 135 of the Bulletin named) arc considered as one. and designated
Potsdam.

CAMBRIAN GLAUCONITES. 339

omy of the individual grains constituting these quartzose masses, for
they present the usual phases of silica as it appears in this type of rocks
everywhere; they are externally well worn and of greatly varying size,
from coarse conglomerates down to the constituent particles of the finest
shale. In many places a green color becomes quite prominent. The
cause of this has not yet been satisfactorily determined; the search for it is
in its experimental stage by the authors with the hope of a demonstra-
tion in the near future. Here it appears to be due to ferrous osfide;
there to a glauconitic mineral ; again the conditions of a chlorite in thin,
bright-green plates are fulfilled. The green constituent, in whatever
phase it occurs, does not seem to possess any cementing quality; yet at
Dresbach, Dakota, and even locally at Winona, there is a coherence far
greater than is usual in Minnesota Paleozoic sands. At these places a
fine white micaceous mineral is very generally present and is regarded
as a kind of binding material. A shaly condition alternates with such
sandstone in Winona county.*

Chemical Composition. — But little can be said touching the chemical
composition of the Potsdam sandstone. Several years ago Mr. PL G.
Klepper made an analysis of this stone from Lansing, Iowa, in the inter-
est of glass manufacturers, with the following result:

Si02 62.93$

0aCO3 1D.0-L

MgCO, 17.0

' ';;

^A\ .- o.oo

99.04%

Tins certainly cannot be an average composition of the Potsdam sand-
stone of Minnesota.

Paleontologic Characters. — In fossil forms the Potsdam horizon is com-
paratively poor. At Taylors Falls several species have been noted, with
fragments of at least three undescribed forms. The rock phases at this
locality deserve mention in connection with the types of life preserved.
The cementing material of the conglomerate is partly dolomitic rather
than wholly arenaceous. The source of the carbonates must lie partly
in the shells of the brachiopods and trilobites and partly in the decom-
position products of the diabasic pebbles, for scarcely any of the finer
ones remain. In percentage of MgO these diabases vary from 2.5 to (i.e..
according to Mr. Sweet. I In secluded hays and inlets animal forms
could find the protection from enemies and quiet seas and supply of food

*Cf. N. II. Winehell; Geologj oJ Minnesota, Final Report, vol. i, 1884, pp. 257 el seq.
fGeologj "i the western Lake Superior District. E. 'I'- Sweet: Geologj <>i Wisconsin, vol. iii.
1880, p. 360.

X I.Y I I'.i i.i . ia.ni,. 8oc. A.m.. Vol 3. 1891,

340 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA.

which enabled them to flourish for hundreds of generations, until their
remains had accumulated to the thickness of many feet. The small
secluded bay at Saint Croix falls was especially adapted for the swarm-
ing of trilobites and lingulas beyond any other spot within the whole
Minnesota Potsdam basin* thus far discovered. It would seem from
the configuration of this basin that when the accumulations of shells
had reached the depth at which currents were felt that the colony dis~
appeared, since the overlying sandstones are epiite destitute of animal
remains. .

The following is the list of fossils known to occur in the Potsdam :
Lingula ampla, Owen; Lingidepis pinnseformis, Owen; Obolella politd,
Hal] : two species of trilobites and one lingula still undescribed, all from
Taylors Falls; other places have thus far shown :

Lingula mosia, Hall.
L. ivinona, Hall.
Ob&ella polita, Hall.
Orthis pepina, Hall.
0. remnichia, N. H.W.
0. sandbergi, N. H.W.
Bellerophon antiquatus, Whitf.
Holopea sweetly Whitf.
■ Aglaspis barrandi, Hall.
Agnostus disparilis, Hall.
A. josepha, Hall.
A. paidis, Hall.
Amphion matittinas, Hall.
Dicellocephalus lodensis, Whitf.
D. minnesotensis, Owen.
D. osceola, Hall.
D. pepinensis, ( )wen.
Ellipsocephalus curtus, Whitf.
Illaznurus quadratus, Hall.

Lonchocephalus chippewansis, Owen.

L. hamulus, Owen.

L. wiscpnsensis, Owen.

Menocephalus minnesotensis, Owen.

Ptycha sj ris granu losa , < ) wen .

P. minuta, Whitf.

P. striata, Whitf.

Ptychoparia anatina, Hall.

/'. bidorsa, Hall.

P. diademata, Hall.

P. eryon, Hall.

P. explanata, Hall.

P. iowensis, Hall.

P. minuta, Whitf.

P. oweni, Hall.

P. perseus, Shu.

P. shumardi, Hall.

P. winona, Hall.

Triarthrella aurunrtis, Hall.

THE MAGyESIAN SERIES.

Subdivisions of earlier Writer*. — This complex series, the Lower Magne-
sian of Owen, consisting of dolomites, shales and sandstones, was first
described by that author in his geological survey of Wisconsin, Iowa
and Minnesota."!" Some conception of the complex character of these

*See Moses Strong, Geology of the upper Saint Croix District: Geology of AVisconsin vol. iii,
1880, p. 417 et seq. ; also Warren Upham, Geology of Minnesota, Final Report, vol. ii, 1888, p. 4ns.
f I8.VJ, pp. 41-71.

WORK OF WINCH ELL, UPHAM AND MCGEE. 341

rocks was foreshadowed in the writings of Keating and other explorers
already cited.

N. H. Winchell in 1873 subdivided the series as follows, in ascending
order :

3. Shakopee limestone ;

2. Jordan sandstone ;

1. Saint Lawrence limestone.

In 1883 Warren Upham, in his study of the geology of Blue Earth
county,* was led to compare the stratigraphy of the Minnesota river val-
ley with that of the Mississippi. In this comparison (in the manuscript
referred to, on page 335, ante) the following series was determined :

5. Shakopee A limestone ;

4. Elevator B sandstone ;

3. Shakopee B limestone ;

2. Jordan sandstone ;

1. Saint Lawrence limestone.

The special item to note in the above is the discovery in Saint Paul,
during the boring of a deep well at Elevator 7>, of a layer of sandstone 20
feet in, thickness in the midst of the upper dolomitic member, the Shako-
pee. With some slight revising and a change in the names of two mem-
bers of Upham 's series, N. H. Winchell in 1887 adopted it and worked it
out in considerable detail f as the most probable sequence of the magne-
sian for this state. The change consisted in adopting the name " New
Richmond " for Elevator B and " Main body of limestone " for Shakopee B,
a term for which " Lower Magnesian limestone'' was subsequently used. J

In the eleventh Annual Report of the United States Geological Survey
W J McGee discusses § the nomenclature of this series. On account of
the vagueness of Owen's descriptions, the obliteration by later investi-
gators of the upper members as they were outlined by him (see ante, p.
334) and the practical abandonment of the series, Mr. McGee adopts the
name Oneota for the middle member. Without tabulating, his classifica-
tion is as follows : the Shakopee A and Elevator B beds are the lower
portion of the Saint Peter of Iowa; the Jordan sandstone and the Saint
Lawrence dolomite and shale are the upper Potsdam of that state; while
the "Main body of Limestone" (Upham's Shakopee B) is the Oneota,
named after " the river upon which the rockmass finds its typical de-
velopment." ||

* Geology of Minnesota, Final Report, vol. i, 1884, pp H5-453.

t< reology of Minnesota, Pinal Report, vol. ii, 1888, preface, p. xxii.

X Ibid., pp. 12, 36, 72, etc.

gThe Pleistocene Eistory of Northeastern towa (op. cit., 1892, pp. 187-577). The authors desire
express grateful acknowledgments to Mr. McGee for his gen irous loan of prool pages i tide,

so far as thej referred to the Minnesota Paleozoic.

|| Ibid., p. 833.

342 HALL AND SARDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

From a comparison of McGee's clear statement of the Iowa Oneota
ami its continuous rocks above and below with the Minnesota series as it
is known to them, the authors feel that the alternation of sands, shales
and dolomites winch occurs in the latter state cannot well be considered
as identical with the Oneota of Iowa. Paleontologic evidence, so far as
it is at hand, bears testimony to the unity of the series between the Pots-
dam and the Saint Peter. Again, the structural, lithological and chem-
ical identity of the beds is remarkable. An oolitic or a breeciated con-
dition is not a marked feature of any one lied, but is found in all three
dolomitic layers alike; the rhombohedral shape of the constituent
grains is an almost universal character of the dolomites, and the chemical
composition of any one layer can be duplicated in either of the others.
These facts are equally true of the sandstones, so far as they will apply.
The deposition in Minnesota was nearer the shore of the Cambrian sea,
and thus exhibits all the phases of sediments from conglomerates through
sands and shales to limestones, which in Iowa may not be the case.
These different phases, for local purposes, must have different name-.
The awkward device "Main body of limestone," first used by Irving*
and subsequently adopted by 'Winch el Id" is shown by McGee to be awk-
ward simply by the use of it in a geologic discussion. Besides the gen-
eral and long-time use of the term Magnesian in Iowa, Wisconsin and
Minnesota, a use which has firmly intrenched the word in our geologic
literature and speech, with and without the qualifying words Upper and
Lower, the dolomitic character of the rocks in question is most perti-
nently expressed in that word. Nowhere else on the North American
continent have we such a vast extent of rocks carrying so typical a dolo-
mitic composition as do the carbonate layers occupying the place between
the Potsdam and the Saint Peter in our northwestern states. The terms
Shakopee, Jordan and Saint Lawrence have been accepted for some years
in Minnesota; their uses have been defined ; the rocks are well known
as a single group ; accordingly in the present paper the term " Magnesian
series " will comprise the following local members :

' Shakopee A (upper Shakopee) dolomite.
Elevator B (New Richmond) sandstone.
Magnesian series. . Shakopee B (lower Shakopee; dolomite.

Jordan sandstone.
Saint Lawrence dolomites and shale-.

In the following discussion but little attention will be paid to these
subdivisions: they are chiefly of local interest, since structural and lith-
ologic characters are almost identical in all similar beds.

* AniiT. Jour. Sei., 3d ser.. vol. ix, 187."'. p. WO.

fGeology of Minnesota. Final Report, vol. ii, 1888, \>. xxii.

SCENIC FEATURES OF THE MAGNESIAN TERRANE. 343

Localities of (hi1 Magnesian Series. — In the Minnesota river valley the
rocks of this series extend continuously from Judson to Shakopee.
Some exposures are at a distance from the stream and others lie in the
banks of its tributaries, as along the Blue Earth; on the Saint Croix
from the neighborhood of Marine to Point Douglas are many conspicu-
ous exposures; on the Mississippi the most northerly masses arc above
Nininger and Langdon, whence they are continuous in a succession of
rugged and castellated bluffs, usually capping the Potsdam, to the Iowa
line: the tributaries of the Mississippi, the Vermilion, the Cannon, the
Zumbro, the Whitewater, the Kollingstone and the Root present many
faces of these rocks; and the sections of many artesian and deep wells
throughout southern Minnesota.

Structural Characters. — Structurally, this series varies more than any
other within the Paleozoic of the state. This arise- from the varied
character of the rocks. The dolomitic portions are massive, and form
those striking scenic effects seen along the streams whose gorges are cut
into or through them. Its thickness is considerable; its walls, through
weathering and corrasion, have been gnawed away until they stand far
apart and face each other with rugged, hoary and castellated fronts.
Trickling waters have produced their effect in moulding the faces of
these walls, or, as in the driftless area* they have removed large masses
of the rock, thus, producing chasms, into which has fallen some debris.
In this manner the many sink-holes have been formed which are to be
seen on the otherwise smooth prairies of this area.

In many localities a brecciated condition is present in the dolomites —
;i condition not infrequent in Wisconsin, according to Chamberlin.f
Ordinarily the chips composing this breccia are not large. In Winona
county a brecciated structure characterizes much of the Saint Lawrence. J
This even appears in some of the silicified material in the upper Shako-
pee. Another feature almost everywhere found in the central lied Cthe
lower Shakopee) is a geodie and concretion;) ry tendency. Silica is thus
collected into segregations of great purity. Redwing and vicinity may
be taken as ;i typical locality. In the dolomitic mass forming Lagrange
mountain, now for some reason more popularly called Barn bluff, there
are numerous segregations of a. light gray microcrystaUine silica, together
with partial fillings which show cavities not infrequently of Large size,
witb walls covered by sparkling facets of quartz crystals. In places these
crystals arc amethystine and of considerable size. An oolitic phase i-

*The Driftless irea of the Upper Mississippi, Chamberlin ind Salisbury, 6th Ann. Rep. U. S.
I. Survey, 1885, p. 205.

t Geology of Wisconsin, vol. i, 1883, p. 140; vol. ii, 1877, p. 278.

fWinchell, N. EJ. : Geology of Minnesota, Final Report, vol. i, 1884, p. 264; ef. G ology^ol [owa,
pt. i, L858, p. 333.

344 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA.

very common, particularly in the uppermost layers of the Shakopee.

This part of the Shakopee carries also that peculiar concretion desig-
nated Cryptozoon minnesotense by N. H. WinchelL* Many specimens
have been found near Cannon falls, at Northfield, and between Man-
kato and Kasota they lie on the prairie in large numbers, weathered out
of the rock. These concretions are associated with thickenings of the
strata, gentle or strong foldings and a varying vesicular condition. Pro-
fessor L. W. Chaney,t who has given some attention to these bodies,
reaches the conclusion that their bulkiness is due to a concretionary
accumulation. This, with the possibly more ready dissolution and re-
moval of the non-concretionary intermediate portions, would account for
the existing wavy condition of the strata.

The shaly condition is occasional in the upper Shakopee, although it
is not a marked feature. It occurs in the Saint Lawrence, and is par-
ticularly shown in well borings from several towns. Indeed these bor-
ings show this member more frequently shaly or arenaceous than other-
wise in the southwestern part of the area.

fr<f^5^fe

Figure 1. — Fault in the Magnesian near Hastings, Minnesota.

1 = Jordan sandstone, standing 30 feet above the railway tracks: -j = lower Shakopee dolomite,
which to the left of the fault is brought down to the level of the tracks and possibly lower.
Sketched from a photograph l>y C W. Hall.

Faulting among these magnesian beds is ^w\\ in several places. The
most notable case is that near Hastings, on the eastern side of the Mis-
sissippi, beside the tracks of two railways, the Chicago, Milwaukee and
Saint Paul and the Chicago, Burlington and Northern. The extent of
slip cannot accurately be determined, but is not less than 50 feet. Fig-
ure 1, sketched from a photograph taken by one of the authors, shows
the relation of the rocks distinctly seen from the railway trains. With-
out discussing the origin of these faults, the opinion may be expressed

*Geol. and Nat, Hist. Surv. Minn.. 14th Ann. Rep., 1885, p. 313.
fBull. Minn. Acad. Nat. Sci., vol. iii, no. 2, 1801, p. 280.

SECONDARY CHANGES IN THE ROCK.. 345

that the dolomitization of* vast beds of Cambrian limestones and the eon-
sequent shrinkage in bulk is alone sufficient to account for the displace-
ments.

The sandstones in all their phases have the usual characters of this
rock. They may briefly be summed up as follows : Structure, massive
and firmly bedded, with occasional shaly layers in local development ;
cross-bedding not infrequent ; in places, indeed, very strongly marked ;
texture, varying through every condition from the conglomeratic to the
finely comminuted ; composition, varying somewhat from clear quartz by
the occurrence of felclspathic and calcareous grains. A cemented condi-
tion of the grains in several counties furnishes a stone which is used for
building purposes,* although such cementing is nowhere found to be at
all extensive, and is no doubt due to an infiltration of carbonates from
an overlying layer of dolomitic rock. The ferruginous appearance seen
in places is due to infiltrated hydrous or anhydrous ferric oxide.

Lithologic Characters.' — -The sandstones may be described in few words.
They are chiefly siliceous. Rarel\T, grains of other material than quartz
are seen save at the bottom or the top of a bed. Within the beds them-
selves there is seldom any coherence. At the edges of the bluffs, where
the carbonates have trickled down from above and cemented the grains,
there is developed a tolerably firm rock, which has some economic
value. Considerable coloring matter, particularly ferric oxide, is locally
introduced. This is often the case in the Minnesota river valley, as at
Ottawa, Lesueur, etc. In places spherical lumps and even huge botry-
oidal masses are formed in the upper sand layers by the trickling down '
of the carbonated waters. At Lanesboro and thence to Hokah, especially
in the Jordan layer, these cannon-ball-like lumps weather out in pro-
fusion. When broken the fragments tend to assume a rhombohedral
form through the cleavage of the calcite constituting the matrix. By
breaking these spherical masses, surfaces several inches across can fre-
quently be secured which exhibit in a beautiful manner the cleavage
planes of* calcite as they are held to the light. This is a very striking
illustration of the strength and persistence of that crystallizing force
which rebuilds broken crystals of the alums, vitriols, etc, for the chemist,
enlarges the quartz fragments throughout whole beds of quartzite, ex-
tends hornblendes and augites in fragmental and eruptive rocks, t and
produces the ophitic structure peculiar to many diabases. A kaolinic
material appears in other places to lie interstitial witli the grains of
quartz, precisely as in the Saint Peter sandstone above.

*Cf. N. II. Winchell : Geology of Mil aota, Pinal Report, vol. i. 1884, p. 253.

to. B. Van Hiee, Enlargement of Hornblendes and Augite9 in Fragmental and Eruptive Rocks :
Amer. Journ. Sci., 3d ser., vol. xxxiii, 1887, p. 386.

SAG HALL AND SARDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

The shales of this scries are hut little known. Well borings at Man-
kato, Blue Earth city and elsewhere show shales with but little crystal-
Unity or coherence. They have a green color usually, which is possibly
due to the presence of ferrous oxide. Everywhere they are partly made
up of carbonates, with a liberal supply of quartz grains.

The dolomitic beds have certain characters of lithologic interest. Along
the Mississippi river at Nininger, Hastings, Redwing, Frontenac and
elsewhere a marked porous condition is frequent. It is more character-
istic of the heavier layers. It is associated with concretions, with com-
pact, finely granular streaks, and with changes in composition in such a
way as to show undoubtedly the secondary origin of the dolomitic feature.
Ordinarily the vesicular structure is not coarse, yet it is readily seen with
the unaided eye. Locally the cavities are larger until a honey-comb
structure appears, or even until the material is wholly removed and a
cavernous condition results, with its recesses beautifully lined with sta-
lactitic incrustations. These seem to be of pure cal cite and are white.
Streaks of a limonitic color occur in the rock. 80 far as they were
examined, they were produced by the infiltration of ferric oxide, which
stains the surfaces of the grains and rhombohedrons which build up the
mass. As a rule, the conipacter portions of the beds are of a much
lighter gray color than the vesicular. Locally a greenish color pervades.

Microscopically there are two persistent characters visible throughout
the series of specimens examined. The first is the rhomhohedral form
of the grains, manifested either in the external form of the individuals
or in their internal cleavage, or in both respects. The external outline
is, indeed, modified by the contact of neighboring particles, yet the be-
ginnings of all the individuals are constantly under the laws of rhom-
hohedral growth (see plate 12, figure 1, compact dolomite from Hastings).
In the coarser phases of the rock this crystallized condition is even
more pronounced than in the finer. In the vesicular portions not only
is the rock itself in this condition, but the cavities are lined with the
projecting angles of rhomhohedra. Where the texture is coarse and the
vesicular structure nearly wanting, numerous spaces occur where clusters
of perfectly formed rhomhohedra are gathered, and each figure has a
border of transparent material whose condition strongly suggests calcite.
Such a phase of the lower Shakopee occurs at Mankato, in the quarries
of the northern portion of the city (see plate 12, figure 2). The sample
was taken 25 feet above the Jordan sandstone. Again, a section taken
from the old quarry at Frontenac, on the Mississippi river 10 miles
below Redwing, shows the vesicular structure very pronounced. The
rhombohedral outline of the individuals is clearly defined, and by a seg-

BRECCIATED STRUCTURE OF THE SHAKOPEE. 347

regation of impurities a distinct tendency to an oolitic structure is fore-
shadowed (plate 12, figure 3, is from a slide prepared from tins Frontenac
dolomite). The rock from the new quarry at the same place has a more
compact structure, a finer texture, and a lighter color. The determi-
nation of purity has not been made by chemical analysis of the speci-
mens from these two quarries. All the compact and vesicular phases
that have been noted can be seen at scores of places among the many
exposures of these dolomites.

The brecciated condition of these rocks and the oolitic phase, which is
also seen, have both been mentioned. Slides prove only the more clearly
what can lie ^rvn with the unaided eye in these phases. The angular frag-
ments which have been thrown together in the breccia show many differ-
ences in texture and in mineral composition; some of them have quartz
grains, others are very fine. The oolitic structure seems to be due to a
molecular or chemical readjustment of the material. But the siliceous
oolite shows certain points of interest in addition to those just named.
While many specimens have been seen from different depths in this
series, the most common occurrence is at the top of the upper Shakopee.
Large masses of microcrystalline silica are found segregated in these
dolomitic layers. It appears that frequently rounded grains of quartz
serve as nuclei around which the silica coming down from the overlying
sands gathers in crvstallographic continuity, building out to a consid-
erable size these small grains, and then becoming imbedded in a matrix
of microcrystalline (chalcedonic) silica (see plate 12, figure 4). These
masses of oolite were doubtless formed in the same way as were the
segregations of .silica so frequently met with, notably at Stillwater, Red-
wing and Winona, only here there are nuclei around which tin' silica
can arrange itself, while there a deposition on surfaces, within cavities,
ami along crevices presents a microstructure partly chalcedonic and partly
agatoid. Thin sections show very beautiful and intricate microgranular
growths.

Chemical Composition. — In chemical composition the dolomites as a
group show a heavy proportion of impurities, particularly silica. When
these impurities alone are considered, there is seen to he considerable
variation in the composition of the beds; when the carbonates are con-
sidered, the variation from a typical dolomite, that is. a rock in which
CaCOj : Mg<'<>:; 1:1 54.4: 15.6, is no more than would naturally be
expected in a rock series underlying many thousand square miles. The
variation alluded to is based on the quantity of these two carbonates in
the nick to the exclusion of all other constituents ; MgC08 is not pitted
againsl the held, as in some instances is the case.

X I. VI I I '.i i i.. i.e. i . Soi , \m.. Vol. :;. 1891.

348 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA.

Below arc given some analyses of these dolomites. A large part of
them have been made in the chemical laboratory of the university of

Minnesota. Those starred (*) were made especially for this paper.

I.*

LI.*

III.*

IV.*

44.78

:;i 26

0.59

18.96

l.mi

v.*

VI.

VII.

VIII.

IX.

XI.

;.1.4ii
40.70

XII.

XIII.

XIV.

1 ll 1 )

47.96

44.4.'.

1.41

5.15

1.1?.

4i'..4C.
18 92

1.7.".
0.43

47.JJ
37.50

0.73
1 ; 01

1.31

:.4.:;4
II 09
ii.Tli
1.84
0.85

50.46
36 26

40.00
31.50

58.65
29.15

48.30
36.80

44.68

31.59

46.86
33.56

48.74

MgC03

l'.i o,

Sio.,

29.27

8.58

3.18

1.72

trace

10.00
5.85

2.73
(1.54
(1.22
0.43

L6.24
5.35

4.71
0.57
l.sl
0.51
38.53
22.7:i
9.26

tV-25
*1.55

f6.90

*4.:in

trace
*4.60

15.50

3.72
2.4:i

12.10
2.99
2.65

13.311

A1203

4.17

1 ..".2

(I.2.".

K .i >

0.26

HoO

0.21

0.37

0.03

2.6.-,

13.70

J3.30

i < i

0.09

0.04

ii.d.-.
(l.mi

\t„(i

i , i

99.30

97.56

99.98 1100.05

98.94

100.20

'.•7.27

99.77

'.in. 2.',

1(1(1.(11}

100.00

'.is. 2:;

117.1'.' 1

I. Compact dolomite, Dresbach : analyzed by C S. Chappie.
II. Compact dolomite. Nininger; analyzed by Mary E. Bassett.
IH. Iiol. .mite, bottom layer quarried at Mankato; analyzed by C. L. Herron.
IV. Dolomite, buff-colored Kasota -ton.'. Kasota; analyzed by H. C. Carel.
V. Dolomite (porous), Frontenac; analyzed by J. G. Cross and E. I'. Sheldon.
VI. Dolomite, Ottawa: analyzed by Professor .1. A. Dodge. ^
VII. Dolomite (eemenl rock), Mankato; analyzed by Professor C. F. Sidener.
VIII. Cement manufactured from Mankato cement stone; analyzed by Professor I '. F. Sidener.
IX. Dolomite; reported by 1'.. F. Shumard, Owen's Geo! Wis.. la. and Minn., p. 484.
X. Dolomite, lake St. Croix, below Stillwater; reported l.y B. F. Shumard, Owen's Geol. Wis.,
la. and Minn . p. .'.'.'.
XI. Dolomite, Gray Cloud island; reported by B. F. Shumard, Owen's Geol. Wis., la. and Minn.,

p 59.
XII. Dolomite, section 20, Lime ; analyzed l.y Professor J. A. Hodge.

XIII. Dolomite, quarry of Maxwell and Mather. Mankato: analyzed l.y Professor J. A. Dodge.

XIV. Dolomite, "eemenl rock," Mankato; analyzed by W. C. Smith.

Paleontohgic Characters. — The fauna of the Magnesian in Minnesota, so
far as reported, is very meager. This is due in part to the imperfect
manner in which fossils are preserved and in part to the fact that sys-
tematic search in these unpromising beds has rarely been attempted.
However, specimens from this series have been incidentally found by the
authors and by others; and it seems probable that a large fauna could

♦ "Alumina, oxide of iron and manganese."
t" Insoluble matter."
j " Water and loss."

PAUCITY OF LIFE IN THE MAGNESIAN.

:;i!)

be worked out. Crinoids, brachiopods, gasteropods, cephalopods, lamel-
libranchs, crustaceans, etc, have been found. In the Shakopee, numer-
ous specimens of Cryptozoon minnesotense, N. H. Winchell, occur both in
Minnesota and Wisconsin, but it is doubtful whether these should be
included as fossils on account of the difficulty of showing their organic
origin and of distinguishing them as they occur from merely folded strata
between which and the concretion-like Cryptozoon there seems to be every
degree of gradation.

The Lower Silurian.
classification of the croc p.

In its area and in the thickness and massiveness of its rocks this group
is greatly subordinate to the upper Cambrian in Minnesota; yet in
paleontologic interest it stands preeminent. Structurally and lithologic-
ally it is divided into limestones and shales. While these subdivisions
are sufficient for ordinary economic purposes, they are of no scientific
value; nor can they be, since they not only merge into one another but
both the limestones and the shales are very far removed from any type
both in physical character and chemical composition. A collection of
fossils such as lies before us, collected and arranged with much care,
develops the following classification of the formations :

Lower Silurian <

Cincinnati

Trenton

Galena.

Trenton

) Wykoff. ( Not subdivided.)

I Maquoketa. (Not subdivided.)
Maclun a.
Lingulasma.
< 'amarelia.
Orthisina.
Zygospira.
Fucoid.
Stictopora.
Stictoporella.
j Blue limestone.
I Buff limestone.
Saint Peter, i Not subdivided.)

In Minnesota t be Saint Peter consists of sandstones ; the Trenton and
< iincinnati of limestones and shales. So far as known to the writers, Mr.
E. < ). Qlrich was the first to apply the name "Trenton shales" to the
extensive series of calcareous shales occupying the upper part, from
Stictoporella to Zygospira, inclusive, of the division Trenton of the third
column above;.

350 HALL AND SARDESON — PALEOZOIC FORMATIONS OV MINNESOTA.

THE SAINT PETER SANDSTONE.

Localities. — There are no exposures of this formation in the Minnesota
river valley except within two or three miles of the mouth of thai stream
and beneath the walls of fort Snelling, where the name was originally
given (see ante, page 333) ; along the Mississippi from Minneapolis to
Newport, on both sides of the river : along Straight river at and near
Faribault and northward from that city in the hanks of Cannon river;
at Castle rock. Farmington, Hampton and New Trier in several outliers;
near Cannon falls; around Pine island; at Saint Charles and vicinity;
in many bluffs along the streams in Houston, Fillmore and Olmsted
counties, particularly at Preston and Fountain.

Structural Characters. — This formation is throughout so extremely
friable that it owes its preservation to the protection of the overlying
Trenton limestone. As a consequence it plays quite an important part
in moulding the topographic features of those counties where it occurs :
streams and underground waters erode it with great rapidity. The rock
is so friable that blocks will not sustain their own weight in handling,
except those taken from the very edge of the exposure, where an infil-
trated cement of calcium carbonate hinds the rounded and smooth quartz
grains together. In such places considerable use can be made of it for
building purposes, bridge construction, etc, as lias been done at fort
Snelling. There is considerable diversity in texture, considering the
formation as a whole, yet more uniformity is seen here than in the Pots-
dam sandstone or in the interbedded sandstones of the Magnesian series.
In Olmsted and Fillmore counties the texture is much coarser than in
Hennepin and Ramsey counties, as well as more uneven.

In much of its thickness the bedding of this sandstone is very obscure.
Frequently bluffs show many feet where a close inspection is needed to
distinguish the lamination. Cross-bedding and slight color alterations
are seen. Here and there bright colors are shown in hands and tortuous
streaks, as at Minnehaha falls, hut no such strong color contrasts have
been noted as are displayed in the sandstones of this formation south-
ward in Iowa* Locally, some tendency to a shaly condition appeal's,
particularly at Highland park and near south Saint Paul. At the last-
named place the lamination is so distinct that, where the layers have
been undermined in securing moulding sand, sheets ten feet or more in
length can lie split off from the overhanging sandstone roof. The posi-
tion of the lamina' here, as everywhere in the state where observed, is

* W J McGee, Pleistocene History of Northeastern [owa: 11th Ann. Rep. V. S. Geol. Survey, 1892,
p. 330.

CONDITION OF THE SAINT PETER SANDS. 35]

horizontal, barring some slight undulations due to fissures and faulting
lines.

Lithologic Characters. — Owen says of this sandstone, "At most of the
localities where it has been observed it is remarkable for its whiteness."*
Tins white color is due to the condition of the surfaces of the grains;
I hey are worn simply to a dead finish — not polished, as can readily he
seen by immersing them in water, when they become limpid. Its white
color is its preeminent character throughout Minnesota. Locally it is
stained red, brown, pink and even green through the infiltration of ferric
oxide, the particular color being due to the quantity or condition of this
oxide. Nowhere is there enough to make a pronounced change in the
chemical composition of the rock. Another element of impurity in this
rock, particularly within the Saint Anthony area, is fine, white kaolin.
Sometimes there is sufficient to render quite turbid the water in a test-
tube in which a spoonful of the sand has been poured. Possibly the
presence of this argillaceous matter coating the smooth quartz grains
prevents the cementation which would convert a clean sand into a
quartzite.f

In speaking further of its purity and fitness for glass-making, Owen
states that an analysis gave but two-tenths of one per cent of foreign
matter, which is alumina, with a trace of carbonate of lime. J < >ne of the
writers several years ago made an examination of the rock at Minneap-
olis and found 98.50 per cent silica and the balance made up chiefly of
alumina; and Professor Dodge, of the university of Minnesota, found
the iron oxide of this Minneapolis rock to amount to only 17 hundredths
of one per cent. Both samples were taken from the unstained layers,
since they were made in the interests of glass manufacture.^

Mr. Julius Hortvet has recently analyzed the fossiliferous sandstone of
south Saint Paul for this paper with the following result:

Si < ). 99.78 per cent.

Fe., 03 trace.

Mg ( ) trace.

Ca, Xa and K were detected by spectroscopic tests. This result is
almost identical with thai of Owen already cited.

In texture this sandstone is somewhat coarser in its bottom layers
than in the middle and upper ones. This seems to be the case at Can-
non falls and Nbrthfiel'd, although nowhere was a conglomeratic texture

Geol. Survey Wis., [a. and Minn., 1852, p. 69.
f A. Geikis says : "It is owing, no doubt, to the purely siliceous character of the grafhs thai the
blending of these »i(li the surrounding cement is so intimate thai the rock often assumes an
almost flinty homogeneous texture." Textbook of Geology, 1st i d., 1882, p. ijt.
J [bid, p. 69.
Bull. Minn. Acad. Nat. Sci., vol. iii. no. I p. L13.

352 HALL AND SARDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

noted nor a mixture of dolomitic pebbles torn from the underlying Mag-
nesian. as is the cast' in Wisconsin* Tiro outliers of this sandstone at
Chimney rock, in Marshan township, and at Castle rock, both in Dakota
county, show sonic strong color markings due to infiltration, and they
show strong cross-bedding and in places a distinct lamination. The dif-
ferent degrees of hardness of the layers induce the interesting sculpturing
which gives name to these exposures, whose existence is doubtless due
to the presence until recently of a cap of Trenton limestone.

Paleontologic Characters. — The fauna of the Saint Peter has until re-
cently been almost unknown. In Wisconsin in 1873 and 1874 Cham-
berlin found scolithus tubes and fucoidal impressions f at Beloit and
Waterloo. In 1875 N. If. Winchell found IAnguhpis morsensisX (which
name was subsequently changed to Lingula morsei by S. A. Miller;; and
in 1884 X. PI. Winchell also recorded the presence of circular pits in the
sandstone at Faribault and Castle rock.§ The writers also have noted
these borings, and on exploring them have found larva' casts ; moreover.
these tubular markings have not been noted in fresh deep exposures ;
hence the fossil nature of the borings is regarded with some suspicion.
< me year ago one of the writers discovered quite a number of fossils in
a small railway cut near Highland park, on the Chicago, Burlington and
Northern railway, a few miles from Saint Paul; these fossils comprised
several genera and species already recognized. || During the present
month (December), at a cut between the Chicago, Saint Paul and Kansas
City railway shops and south Saint Paul, fossils were found in large
numbers, all comprised, however, in three or four species. The sand-
stone in which these last fossils were found is almost pure white. Chem-
ically it is nearly pure silica. It was this fossiliferous rock that Mr.
Hortvet analyzed with the result given on a preceding page. In both
localities the shells are wholly absorbed. At Highland park a stain of
ferric oxide covers the walls of the casts; yet the growth markings are
distinct. Near south Saint Paul the walls are perfectly smooth and show
distinctly muscle impressions, as well as growth striae. These markings
are easily obliterated with careless handling, owing to the extreme fria-
bility of the rock. The study of this newly discovered fauna is in prog-
ress : yet enough is already known to show that it is thus far almost wholly
molluscan. Murchisonia gracilis, Hall, M. perangidaia, Hall, with four

other gasteropods ; two new species of Modiolopsis ; Tellinomya, sp. undet. :

* Charoberlin : Geology of Wisconsin, vol. ii, 1*77, p. 287.

j If »id.. p. 288

I Geological and Natural History Survey of Minnesota, Ann Rep. for 1875, p. 41.

ogy of Minnesota, Final Report, vol i. 1884, p. 656.
|| F. W. Sardeson : Fossils in 1 he Saint Peter Sandstone. Bull. Minn. Acad Nat Sci., vol. iii, no. ::,
1892, p. 318.

UNCONFORMITY OF SAINT PETER AND M AON ESI AX.

353

and Endoceras, sp. undet., are among the specimens obtained. They
show the distinctively Lower Silurian character of the Saint Peter sand-
stone.

Physical Relations. — There are some points in the structural characters
of this formation which lead the authors to regard it as a transition lied
between the Cambrian and Silurian periods.

1. In the first place, the Wisconsin geologists have proved that for
many localities the Lower Magnesian is an eroded formation. This ero-
sion represents within their area a period of cessation in the deposition
of rock material. Several of them have described the conditions observed
and have in several figures represented the unconformity of the Saint
Peter upon the Lower Magnesian — i. e., Cambrian. T. C. Chamberlin,
in Ins report on the geology of eastern Wisconsin, mentions places where

Mil

1 1 1 1 i i i i i I I I I I I I

i i i i i i i i i i i i i i i i i i i

i i i i i i i i i i 1 i" i i i i r i i i i

i ' i i i ' i i i i i i i I i I I I i i i i i i i i i

ill i i i i i iii i ii i i i i i i i i

Figure 2.— Unconformity of the Saint Peter on the Magnesian and the Conformity of the Trenton on
the Saint Peter *

1 = Magnesian ; 2 = Saint Peter; 3 = Trenton.

the former lies upon the eroded edges of the latter, and in instances cited
its upper surface is many feet below the crests of the bower Magnesian
ridges.f He also cites localities where the Saint Peter is wholly wanting
and the Trenton, winch has been preserved throughout the erosion
which this region has subsequently undergone, lies directly noon the
bower Magnesian.J No such evidence as this has been found in Minne-
sota thus to establish the boundary between the Cambrian and Lower
Silurian at the base of the Saint Peter. < )n the contrary, this formation
is everywhere found in thickness varying from 75 S to 16 1 feel beneath the
Trenton.

* Diagrammatic section from Chamberlin. Geol. Wis., \ ol. i. 1882, p i 15.

; i leology of Wisconsin, vol. ii, 1*77, |> 27 I.

| [bid., p 285.

gN. II. Winchell : Geology of Minnesota, Final Report, vol, i. 1884, p 219.

354 HALL AND SAJRDESON PALEOZOIC FORMATIONS OF .MINNESOTA.

One of the authors while collecting lower Paleozoic fossils in southern
Wisconsin had occasion to note quite closely the relations of these for-
mations now under consideration. His observations convinced him that
the Lower Magnesian was folded locally into a succession of ridges and
depressions. Every character showed this folding to be due to lateral
pressure. The structural appearance, the uneven character of the folds,
and the parallelism of the lamination of the rock and the configuration
of the Saint Peter strata on the dolomite beneath, all pointed to that cause.
The lamime of the two formations were perfectly conformable. The con-
clusion is that the folding of tic M«j/nesiui) cxt> adrd upicurd and involved
the Saint J'i U r.

The conditions above cited were se -:i in the Pecatonica valley, hi 'tween
Blanchardville and the Wisconsin-Illinois boundary, at several different
localities: and a similar folding of the Magnesian has already been men-
tioned as occurring at Northfield, Minnesota.

2. Considering now the Saint Peter alone, we note that at south Saint
Paul it shows many minor faults. In regradinp; a street from the Chi-

WSMISSmmmz

wmmrn^

Figure ?,. — Minor Faults and Color Markings of the Saint Peter Sandstone at. south Saint Paul.

1 = Normal Saint Peter sandstone, colored along lines of bedding ; 2 = Saint Peter sandstone,
colored aud cemented by infiltrations from above, and covered by a layer of river gravel mingle. 1
with bowlders.

cago. Saint Paul and Kansas City railway shops to the south Saint Paul
packing-houses considerable cutting has been done in the side of the
sandstone bluff along which the street extends. - These fresh exposures,
a quarter of a mile or more in length, afford an excellent opportunity to
study the structural features of the middle portion of this formation.
These faults are of interest, too, in that they Occur in almost incoherent
sands, just as clearly defined as in the tinner and more sharply lami-
nated beds. The faults are sometimes vertical, yet oftener inclined in
various direction-, prevailingly north and south. Figure 3 sketches
these fault-.

•">. In the third place, at a number of localities, particularly within the
Saint Anthony area, opportunities are afforded for studying the contact

DEFORMATION OP THE SAINT PETER. 355

of the Saint Peter sandstone and the Trenton limestone. Nowhere is
there any indication, however slight, of an unconformity. The transi-
tion zone of a green shaly calcareous sandstone shows the steady oncom-
ing of that Lower Silurian sea which, if it did not submerge the whole
Northwest, at least extended so far that the dry land was reduced to
islands or narrow peninsular stretches of very uncertain connection with
a mainland lying somewhere. For a considerable distance below this
contact zone the sandstone shows no such faulting or jostling of the
strata as can be seen in the spot already mentioned, estimated to lie from
75 to 90 feet from its base. The same may be said of the exposures of
the Saint Peter in the southern area, notably at Cannon falls, Faribault
and Fountain, where the beds are exposed for a considerable distance
from the top downward.

' , ', I I , I I I ,1 ,1 ' , I, l, ,1 , !

I II III II 1 I II

Figure 4.— Diagrammatic Sketch showing the Relations of the Magnesian, Saint Peter and Trenton.

1 = Magnesian with gentle fo.lding; 2 = Saint Peter folded with the Magnesian in its bottom layers
and displaced by faults, which extend upward but disappear before the topis reached; 3 = Trenton
i Bun i limestone conformable with the Saint Peter.

From the three considerations pointed out we conclude that this sand-
stone which geologically occupies so important a place in Michigan (?) *
Wisconsin, Minnesota, Iowa, Missouri and Illinois, represents, for Min-
nesota at least, a great transition epoch between Cambrian and Lower
Silurian time. It stands for the interval between the close of the depo-
sition of those rocks which are now dolomites, whatever they once might
have been — an interval which in eastern Wisconsin was one of dry land
and erosion, — and that succeeding period of long-time permanent Silu-
rian seas with their varied fauna and well defined flora.

These physical conditions and the fauna! characters recently discov-
ered seem to us to place beyond all question the Saint Peter sandstone
of the northwestern states in the column of bower Silurian epochs, and

Geologj "i Wisconsin, vol. i, 1877, p. L49.
XLVIU I'.i i.i . Geol. Soc. A.m., Vol. 3, 1891.

35G HALL AND SARDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

for these states at the very base of that column. This relation is shown
in figure 4.

It may further he said that the Saint Peter was involved with the re-
mainder of the Lower Silurian in the movements which brought about
the gentle minor undulations seen in the latter at many places in south-
eastern Minnesota, and in the major wave whose crest is shown on the
profile drawn at the bottom of the map (plate 10) accompanying this
paper.

THE TRES TOX LIMESTONES AND SHALES.

Localities. — In many different townships of Fillmore and Olmsted
counties, at Saint Charles and Clinton tails, around Faribault, near
Elgin, at Cannon falls and southward to Kenyon, at Berne, Old Con-
cord, Belle creek, Farmington and Mendota, in several outliers in Wash-
ington county, and at numerous places in the cities of Minneapolis and
Saint Paul, the Trenton rocks occur.

For convenience in description, the foregoing localities will he grouped
in two areas, viz, the Saint Anthony area and the Southern area. The
former comprises those exposures of Lower Silurian rocks within twenty
miles or so of Saint Anthony falls, where the Mississippi breaks over the
shelf of Trenton limestone almost at the northern limit of the formation ;
while the latter includes all those exposures within the state south of
Hastings and Farmington. This is, in the area underlain by its rocks,
by tar the more important of the two.

Structural Characters. — These characters are extremely varied. There
is almost every phase of a stratified rock from a compact massive lime-
stone to a thinly laminated, fissile, carbonaceous shale. They will he
chiefly considered in connection with the paleontologic characters of the
different beds into which the representative fossils appear to divide the
formations. Here, however, it may be stated that, resting upon the green
and somewhat shaly top of the Saint Peter, there lies in a stratum of some
inches in thickness, hut with no well defined upper boundary, a blue-
green-gray finely textured rock which lacks adhesion to such an extent
as to crumble and become worthless. The limestone above contains
numerous interrupted layers of this crumbling material. These layers
cause the rock to separate easily on exposure, thus becoming an inferior
building stone unless laid in the same horizontal position as they occupy
in the quarry. Many joints occur, and sometimes they can be traced
hundreds of feet. Only one or two cases of faulting are known.

Lithologic Characters. — A discussion of these will be restricted largely
to the more compact lower layers, since the shales are very difficult to

STRUCTURE AND COMPOSITION OF THE TRENTON. 357

section by reason of the generally uniform composition and structure

throughout and the absence of well defined and constant stratigraphic
elements.

The lower contact zone just mentioned gives in part areas of calcium
and magnesium carbonates and in part clusters of kaolinic material and
grains of quart/,. The general aspect is that of a rock whose original
characters have become in great part obscured by infiltration of new
material.

The next layer above this contains hands of quite pure calcium car-
bonate often several inches thick. Scattered through these bands are
occasional clusters of pyrite and granules of carbonaceous matter. The
argillaceous bands which alternate with these show a finely crystalline
granular matrix, in which lie rhombohedrons of calcite (see figure 5,
plate 12). This layer readily crumbles on exposure to the air, causing
the compacter limestone bands to separate. The chemical composition
of this layer and that of other portions associated with it will soon be
given, when conditions will be seen which explain the crumbling and
great lack of cohesion which the rock presents. The layer above this
fails to show the banded character just mentioned, but its proportion of
alumina, silica and ferric oxide is also very marked. Within it pyrite
often becomes clustered in quite large nodules, and the cavities from
which the fossils have been absorbed contain on their walls incrustations
of beautiful calcite and pyrite crystals, both single and clustered. Well
developed rhombohedrons also characterize many portions of this layer*
Nowhere have the writers observed the presence of twinning in these
rhombohedrons, although cleavage is usually distinct.

Chemical Composition. — This has always been a matter of great interest
to those who have examined the formation Owen, who called the
Trenton the ''Saint Peter's shell limestone" from its richness in organic
remains, stated that the lowest bed contained 65 per cent CaC03 and 13
per cent MgCO, and pronounced it a poor hydraulic limestone.t Many
analyses have been made in the chemical laboratory of the university of
.Minnesota. These analyses represent particularly the layers which have
some economic value, especially for building stone, for which the rocks
of the lower calcareous division of the formation are largely used. The
following table contains those of present interest :

*C. W. Hall, Lithological characters of tli- Trenton lim istone, etc: Hull. Minn. Acad. Nal Sci
vol. iii, ii" 1. 1889, |>. 1 Is.
•{•Geology of Wisconsin, [owa and Minnesota, 18-12, \>\>. 71, 72.

358 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA.

II.

III.

IV.

VI.

VII.

VIII.

CaCO

79.18

6.38

trace

0.04

8.16

2.(17

f2.43

trace

0.80

83.24

5.40

0.13

trace

5.79

2.04

fl.89

trace

0.46

56.47
14.21
trace

0.14
15.84

4.93
f4.00
trace
trace

L.26

2s.se,
11.18

80.60

18.00

77.21
3.91

36.40
0.40

70.5:;

MgCO,

23.49

( 'a* ) combined with Si< )., . .

IMgl 1 combined with si< >., .
Sii ),

20.38

2(1.77
fl5.31

1.30
1.30

1.20

9.99
3.43
2.69

*29.00

! 12.40

4.57

Al2Os

K,( ).

o.7i;

Na2< )

1 Irganic matter

H,( )

trace

1.91

Jl 8.00

Total

99.66

98.95

96.85

102.50

102.40

99.14

96.20

99.32

I. The Buff limestone ; the rock analyzed as a whole. Professor J. A. Dodge,

university of Minnesota.
II. The Buff limestone ; the clean calcareous portions with the dark alumino-
siliceous bands removed. Professor J. A. Dodge.

III. The Buff limestone; the dark ahunino-siliceous bands with the calcareous

portions removed. Dr. W. A. Noyes.

IV. The lower strata of the Blue limestone; those that crumble on exposure

to the air. Horace V. Winchell.
V. The Buff limestone. Miss M. L. Blanchard.
VI. The Buff limestone. W. A. Beach.

VII. The lower (first) strata of the Blue limestone; probably the same as IV.
Dr. Norwood.^
VIII. Galena limestone ; section 9, Spring Valley. Chemist unknown.

g these

Paleontologic Characters: The general Section. — In presentin
characters of the Lower Silurian rocks (aside from the Saint Peter,
already briefly described) many structural features must be detailed
which for this very reason were omitted from the paragraph purporting
to outline those characters. Furthermore, many facts will be presented
which have been discussed more in detail in another place. || The names
here given to the second beds are those proposed in the article referred to.

So far as observed, the lowest Trenton bed of the state, the Buff lime-
stone (lower Buff of the Wisconsin series),^) rests conformably on the
Saint Peter, save at Faribault, Rice county, where the bed is absent, thus
bringing the Blue limestone upon the sandstone and in conformable
position. From this point up to the top of the Silurian series for the
state there has not been seen either break or unconformity, though the

* Insoluble silicates.
•1 Fe2Oa and FeO calculated together.
% Loss, 3.80 per cent, also reported.

§ Geological Survey of Wisconsin, Iowa and Minnesota; Owen, ls-"^. p. 72.

It The range and distribution of the Lower Silurian Fauna of Minnesota, etc, by F W Sardeson .
Hull. Minn. Acad. Nat. Sci., vol. iii. no 3. 1892, pp 326-343.
\ Geology of Wisconsin, vol. i. 1883, \>. 102.

THE LOWER SILURIAN SECTION.

359

beds vary somewhat in thickness and dip in certain localities. The dip
of these rocks in Minnesota is not uniform over any large area, but weak
anticlinals and synclinals are frequent. The Galena dips several degrees
toward the south in the quarries near Owatonna; in the quarry at Ken-
yon there is a marked synclinal and at Faribault a slight dip ; at Cannon
falls (in N. E. \ sec 31, T. 112, R. 18 \V.) the beds of the Galena are so
much below those of a neighboring lower horizon (in sec. "2'.), same town-
ship) as to be confusing unless lithologic and paleontologie data are relied
upon. The Lower Silurian in Minnesota is undulating as in Wisconsin,
only not in so strong folds.

The following is a summary description of the several beds (figure 5) :

r-i

WyXoff beds

So:

Maquoketa Shale zo'. PI

Maclurea bed

Llngulasma bed

Camarella bed

Orthisina bed

Zysrospira bed

Fucoid bed

Stictopora bed

St let op ore I la J>ed
Blue Limestone

Buff Limestone

is:

Saint Peter beds /So:

Jo' |

»'•"■ -.'••:T-' ■•: j •-... ■■■■" *»
I — ■.,.— --_ — ^J :— —

Fiai re 5, - Classification of the Lower Silv
\ cortical section representing the relative thickness of the several b< Is, their lit 1 1 •
and their distincl ive faunal types.

- I l;> 1-

360 HALL AND SARDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

The Buff Limestone. — This is 15 feet thick. It has the constant char-
acter of being made up of somewhat irregular laminae, usually composed
of alternating hard, firm limestone and softer, darker colored argillaceous
1 lands. The action of percolating waters may render these strata porous
by removing the more soluble parts. On the other hand, it may render
them more crystalline by their metamorphosing effect on those constit-
uents remaining behind. In the former case fossils are reduced to mere
casts and cavities; in the latter they are entirely destroyed. At Minne-
apolis this layer preserves more fossils than it does further southward.

The following fossils occur in this bed :

Cm a in trentonensis, Hall.
Leptsena sericea, Hall.
Orthis deflecta, Conrad.
0. j" /'■' ta, Conrad.
0. tricenaria, Conrad.
Rhynchonella orientalis, Billings.
Skenedium anthonensis, Sardeson.

Streptorhynchus filitextum. Hall.
Strophomena minnesotensis, N.

Winchell.
Zygospira aquila, Sardeson.
Cypricarditis rotundatus (?'), Hall.
ModiolopsU meyeri, Billings.

The Blue Limestone. — This layer is 12 feet thick. It lies directly
upon the Buff limesh me just described, save at Faribault. The two beds

■ M-f.v ^.i sn

xtrr- ^..iQll W,4-. j.;..

ttrT^,? T.rV> , ■ y

Figuke 6. — Lenticular Segregations of Fossils in the Blue Limestone, Minneapolis.

The lenses represent the deposition of vast numbers of fossils within restricted areas. The
shells have totally disappeared, leaving only easts of the interiors.

are separated by a, distinct change in rock texture and usually, though
not always, by a carbonaceous seam. The Butt' separates along lamina'
determined by the argillaceous bands; the Blue lies in heavy strata
which break in all directions with a conchoidal fracture. The lower
half is more crumbling when exposed and presents few fossils save in
lenticular horizontal seams. These seams show how the fauna dwelt in
colonies. For one or three inches in depth and stretching out over 100
or 200 square feet, the rock is wholly made up of casts of fossils whose
surfaces carry coatings of calcite and pyrite crystals, while the rock for
some distance above and below shows scarcely a trace of fossils (see
figure 6). From the very uppermost stratum a few well preserved shells

THE LIFE OF THE TRENTON SEA.

301

weather out. Rarely the Blue and the Buff beds become somewhat
alike lithologically through the effect of destroyed fossils.

The fossils of the Blue limestone are —

Cm a itr trentonensis, Hall.
Discina concordensis, Sardesou.
TAngula elderi, Whitfield.
Lingulella iowensis, Owen.
Orthis bellarugosa, Conrad.
0. deflecta, Conrad.
0. pervi ta, ( Jonrad.
0. tricenaria, ( lonrad.
Rhynchonella minnesotensis, Sarde-

son.
Strt'j>t<>rlii/itrli/is filifi .rtn in. Hall.
S. minnesotensis, N. H. Winched.
Zygospira recurvirostris, Hall.
Z. aquila, Sardeson.
Bucania bidorsata. Hall.

Helicotoma planulata, Salter.
Maclurea bigsbyi. Hall.
Murchisonia gracilis, Hall.
M. milleri, Hall.
,1/. tricarinata, Hall.
Pleurotomaria subconica, Hall.
Raphistoma lenticulare, Emmons.

B. nasoni, Hall.

Subulites elongatus, Emmons.
Trochonema beloitense, Whitfield.
< 'ypricardites rectirostris, Hall.

C. niota, Hall.
Tellenomya nasuta, Hall.
Modiolopsis plana, Hall.

The Stictoporella Bed. — The Buff and Blue limestones described above
constitute the true Trenton limestone in Minnesota. The 10 feet here
described as the Stictoporella bed is, however, partly composed of lime-
stone strata from two to sixteen inches thick. But they are crystalline,
very firm and compact strata, often called marble in the west. They
contain few fossils except at their surfaces, hut alternate with richly fos-
siliferous strata of shale.

In the Saint Anthony area, particularly within the cities of Minneap-
olis and Saint Paul, the proportion of crystalline limestone to the shale
is about one to two, with the former predominating at the bottom. The
junction with the Blue bed is defined either by a granular seam or a car-
bonaceous hand, or less frequently by a sudden transition to " marble."
While the succession of strata is somewhat variable, it is broadly stated
as follows: A stratum of purple crystalline stone (> to 8 inches thick : a
thin layer of shale: a gray crystalline stratum is to 24 inches thick:
shale : bluish limestone 6 to s inches : and shale with thin strata of lime-
stone and carbonaceous laminae to the top of t he series. In the southern
area limestone layers predominate over the shale.

The name given to this series of layers is suggested by the abundance
of remains of Stictopon lla.*

• The names Stietopori lift and St i given to two of these Lower Silurian beds are from two
genera of bryozoa abundant in them and ii the same time s< whal restricted (■> them, ;c- deter-
mined and described by E. 0 Ulrich, Geol and Na< His! Mir. Minn., Ann. Rep for 1885, pp. Ci

302 HALL AND SARDESON — PALEOZOIC FORMATIONS OF MINNESOTA.

The fossils are :

Analoteichia impolita, Ulrich.
Pachydictya foliata, Ulrich.
Stictoporella frondifera, Ulrich.
Leptsena sericea, Sowerby.
Lingula elderi, Whitfield.
Orthis perveta, Conrad.
0. tricenaria, Conrad.
Rhynchonella ainsliei, X. H. Win-
chell.

R. minnesotensis, Sardeson.
Streptorhynchus filitextum, Hall.
Zygospira recurvirostris, Hall.
Helicotoma planulata, Salter.
Murchisonia gracilis, Hall.
Pleurotomaria subconica, Hall.
Raphistoma lenticulare, Emmons.
Productella Minneapolis, Sardeson.

The Stictopora (or upper Blue) Bed. — This layer has a thickness of
about 30 feet. It is made up of a dark-green rock, massive rather than
shaly in its structure, and quite argillaceous in its composition. It car-

Piguee 7. — Lenticular Segregations of Fossils in the Stictopora Bed, Saint Paul.

Lenses consist of closely packed and thoroughly cemented fossils within the muss of calcareous

shale.

ries a few crystalline slabs composed of firmly cemented fossils (figure
7). This bed weathers so rapidly as to give it the appearance of being
very fossiliferous, but it is probably less so than the beds above. It
affords a good illustration of effectual weathering when exerted on rock
made up of such diverse elements.
The fossils are :

Raufi lla filosa, Ulrich.
R. palmipes, Ulrich.
Pachydictya jimbriata, Ulrich.
Phylloporina reticulata, Hall.
Prasopora contigua, Ulrich.
Stictopora mutabilis) Ulrich.
Stictoporella cribrosa, Ulrich.
('nut in halli, Sardeson.
C. setigera, Hall.
C. trentonensis, Hall.

Zygospira recurvirostris, Hall.
Bellerophon hiloLittnx, Sowerby.
Bucania bidorsata, Hall.
Cortchopeltis bbtusa, Sardeson.
Cyclonema semicarinatum, Salter.
Holopea symmetrica, Hall.
Murchisonia gracilis, Hall.
M. milleri, Hall.
M. tricarinata, Hall.
Pleurotomaria clivosa, Sardeson.

LOWER TRENTON FOSSIL BEDS.

606

Lepta nit si ricea, Sowerby.

Orthis bellarugosa, < lonrad.

0. subsequata, Conrad.

0. testudinaria, Dalman (variety).

0. tricenaria, Conrad.

Rhynchonella ainsliei, N. H. Win-

chell.
R. minnesotensis, Sardeson.
Streptorhynchus filitextum, Hall.
Strophomena alternata (/), Conrad.
S. halli, Sardeson.
S. inquassa, Sardeson.

P. mbconica, Hall.
Raphistoma lenticulare, Emmons.
Subulites elongatus, Emmons.
Trochonema umbilicatum, Hall.
Cypricardites subtruncatus, Hall.
C. ventricosus, Hall.
Modiolopsis plana, Hall.
M. superba, Hall.
M.faba, Emmons.
Tellinomya levata, Hall.
T. ventricosa, Hall.
Whitella compressa, Ulrich.

The Fucoid Bed. — This is 20 feet thick, consisting chiefly of very argil-
laceous material so abounding in fucoidal remains that the name Fucoid
is given. It differs from the underlying Stictopora bed in being full of
calcareous and siliceous laminae, besides masses of sponges, Raufella fili-
osa and R. palmipes, and various bryozoa. There are also thin layers of
limestone from one to six inches thick, of which one is markedly oolitic
and limonitic. In these respects this layer reminds one of the oolitic top
of the upper magnesian layer, Shakopee A. This oolitic-limonitic layer
has been recognized in Ramsey, Goodhue and Fillmore counties. The
uppermost strata are of firm crystalline limestone, 3 feet in thickness at
Saint Paul. It may prove to be less firm in the Southern area of the
formation.

The fossils are as follows :

Phylloporina corticosa, Ulrich.
Prasopora contigua, Ulrich.
P. conoidea, Ulrich.
Pachydictya occidentalism Ulrich.
Stictopora mutabilis, Ulrich.
('run in setigera, Hall.
Leptssna sericea, Sowerby.
Orthis minnesotensis, Sardeson.
0. pectinella, Emmons.
0. subssquata, ( lonrad.

0. rogata, Sardeson.
0. trici naria, Conrad.
Rhynchonella increbescens, Hall.
Streptorhynchus filitextum, Hall.
Strophomena alternata, Conrad.
S. minnesotensis (/), N. H. Winch ell.
Zygospira recurvirostris, Hall.
Mufchisonia milleri, Hall.
Pleurotomaria subconica, Hall.
Subulites elongatus, Emmons.

The Zygospira Bed. — A layers fret thick from the top of the Fucoid
bed upward has been separated mainly on paleontologic grounds ; yet it
may be distinguished from the Fucoid bed by the presence within it of
numerous rounded calcareous masses rather than calcareous laminse
such as those of superior member.

XI. IX Bun. Gkol. Soc. Am., Vol. 3, 18U1.

3G4

HALL AND SARDESON" — PALEOZOIC FORMATION'S OF MINNESOTA.

The fauna is meager in species, yet remarkably abundant in indi-
viduals. It is as follows :

Pachydictya occidentalism Ulrich.
Stictopora mulabilis </), Ulrich.
Leptsena minnesotensis, Sardeson
Orthis minnesotensis, Sardeson.
0. pectinella, Emmons.
0. rogata, Sardeson.
0. tricenaria, Conrad.

Pkolidops trentonensis (?), Hall.
Rhynchonella increbescens, Hall.
Streptorhynchussubsulcatum,Sa,rdeson.
Strophomenct alternata, Conrad.
Zygospira recurviroslris Hall.
Bellerophon bilobatus, Sowerby.
Modiolopsis recttformis (?), Worthen.

The Orthisina Bed. — This bed is of varying thickness. It may be
considered, perhaps, the first of the Galena 1 mm Is. It is made up of shaly
limestone, shales with calcareous lumps and firm but thin calcareous
strata. Fossils are very numerous, both in individuals and species:
mollusca are well preserved in the calcareous parts and molluscoidea in
the shales. It is well exposed at Kenyon. The name is given from one
of its characteristic species.

The fossils are —

Receptaculites iowt nsis, Owen.
R. vice ni, Hall.

Pachydictya occidentalism Ulrich.
Leptsena minnesotensis, Sardeson.
Lingula recinaformis (?), Hall.
Or/hi* biforata, Schlotheim.
0. minnesotens-is, Sardeson.
0. rogata, Sardeson.
0. trict mi rin, ( 'onrad.
Orthisina americana, Whitfield.
Pholidops trentonensis (f), Hall.
Rhynchonella increbescens, Hall.
R. sancta, Sardeson.
Streptorhynchus filitextum, Hall.
S. subsulcatum, Sardeson.
Strophomena alternata, Conrad.

Zygospira recurvirostris, Hall.
Bellerophon bilobatus, Sowerby.
Bucania bidorsata, Hull.
B. buelli, Whitfield.
B. punctifrons, Emmons.
Fusispira elongata, Hall.
Holopea perundosa, Sardeson.
Murchisonia alexandra, Billings.
M. bellicincta, Hall.
M. gracilis, Hall.
M. in ilb ri. Hall.

Raphistoma A nticulare, Emmons.
Subulites elongatus, Emmons.
Trochqnema umbilicatum, Hall.
Tellenomya asiartseformis, Salter.
Whitella truncata, Ulrich.

The Camarella Bed. — This member of the series is 30 feet thick. The
bed is composed of carbonaceous limestone which quarries very well, yet
splits into thin irregular lamina' when exposed to the air. It is quite
impregnated with iron pyrites with some chalcopyrite intermingled. It
is separated quite sharply from the Orthi.-simt lied aim differs from it in
possessing few fossils, as well as in faunal and lithologic characters. Its
fossils are —

TYPICAL TRENTON FOSSILS. -'505

Camarella bemensis, Sardeson. 0. rogata, Sardeson.

Q. hemiplicata, Hall. Streptorhynchus rhomboidalis, Wilck-

C. owatonnensis, Sardeson. ens.

Crania trentonensis (?), Hall. Strophomena minnesotensis (f), N. H.

Distinct concordensis, Sardeson. Winchell.

Leptsena minnesotensis, Sardeson. Zygospira recurvirostris, Hall.

Lingulella iowensis, Owen. Bellerophon bilobatus, Sowerby.

Orthis beUarugosa, Conrad. Fusispira elongata, Hall.

f>. biforata, Schlotheim. i^. ventricosa, Hall.

The Liiif/iila.snifi Bod. — This division is 20 feet thick, consisting of very
heavily bedded limestone and containing few fossils or impurities of any
kind. In places it is strikingly colored by infiltration bands. From
this appearance it is by quarrymen called a sandstone, although desti-
tute of quartz grains. It is an excellent building stone. In fossils it
carries —

Distinct concordensis, Sardeson. 0. biforata, Schlotheim.

Lingidasma schucherti (/), Ulrich. 0. rogata, Sardeson.

Lingulella iowensis; Owen. Bucania punctifrons, Emmons.
Orthis beUarugosa, Conrad.

The Mad it rat Bed. — This is a coarsely bedded limestone. In weather-
ing it passes into a coarse porous rock strongly resembling a sandstone
hi some respects; it develops a marked staining through the infiltration
of ferric oxide along its joints. Perpendicular bluffs exposing all or
nearly all of its thickness are quite common.

Its fossils are few but. for the Minnesota Silurian, of unusually large
size. On account of their rarity they can be found only where large
quantities of rather fresh debris are accumulated in quarries and the
gorges of streams. These have been noted :

Receptacidites oweni, Hall. Maclurea cuneata, Whitf.

Fusispira elongata, Ball. .1/. major, Hall.

/•'. ventricosa, 1 1 all.

Till: CINCINNATI LIMESTONES AND SHALES.

'lite Maquoketa Beds: Localities. — These beds are displayed at Granger,
three miles wesl of Forestville, and near Spring Valley ; everywhere in
small exposures.

Structural Characters. — This is a heavily bedded crystalline Limestone
alternating with beds of shale. The limestone predominates in the Lower
layers and the shales in the upper. The shales may easily be mistaken
in Lithologic and structural characters for the Stictoporella bed of the
Trenton. The thickness of these rocks in the exposures \ Lsited is about

366 HALL AND SARDESON PALEOZOIC FORMATIONS OF MINNESOTA.

20 feet. The entire thickness is not known, since at no single exposure
have both top and bottom layers been seen; but it is estimated at 30 or
more feet. The limestone layers contain trilobite and Endocerasm remains
in good preservation. The shales contain the remains of a few species of
molluscoidea in great numbers.

Lithologic Characters. — The crystalline condition of portions of these
shales has just been mentioned. The typical hand specimens show a
strikingly mottled stone, which displays varying shades of light brown,
faint yellow and white (see plate 12, figure 6). In texture it is much
finer than the average Lower Silurian limestones or somewhat massive
shales. It is not thoroughly crystalline, but is made up of partially
crystalline material, with immense numbers of minute fossils, apparently
of many and diverse species.

Paleontologic Characters. — The following fossils have been identified:

Leptsena prsecosis, Sardeson. Strophomena alternata (/), Hall.

Orthis corpulenta, Sardeson. S. unicostata, M. and W.

Streptorhynchus trilobatum, Owen.

The Wykoff Beds: Localities. — These beds are seen in Fillmore comity,
between Wykoff and Spring Valley, and at Spring Valley in exposures
along the Chicago, Milwaukee and Saint Paul railway. In the town of
Bristol, near Granger village, there are several small exposures.

Structural Characters. — The Cincinnati limestone of Minnesota under
the above designation, one suggested by the prominent characters it dis-
plays near the village of Wykoff, in the western part of Fillmore county,
is rather heavily bedded. It is only 20 to 25 feet thick along the railway
named, but it becomes 70 feet or more in thickness only 15 miles further
southward along the Iowa line, in Bristol. It is easily eroded, and a
shaly appearance is the first and most conspicuous result of this action.
In fact the term " shale," which has sometimes been applied to this
scries of strata, by no means expresses its lithologic or structural condi-
tion when fresh and unaltered material is seen.

Paleontologic Characters. — The following fossils are known :

Leptsena recedens, Sardeson. S. wisconsensis, Whitfield.

L. saxea, Sardeson. Strophomena alternata {?), Hall.

Orthis corpulenta, Sardeson. S. unicostata, M. and W.

0. hanhdkensis, McChesney. Bellerophon bilobatus, Sowerby.

0. ma.crior, Sardeson. Murchisonia gracilis, Hall.

O.petrse, Sardeson. Pterinea demissa. Hall.

0. subquadrata, Hall. Tellinomya lepida, Sardeson.

Rhynchonella capax, Conrad. Modiolopsis modiolaris, Hall.

Streptorhynchus trilobatum, Owen.

TYPICAL LOWER SILURIAN FOSSILS. 367

The lists of fossils from the Lower Silurian thus far given arc inten-
tionally limited mainly to certain abundant and representative classes.
In addition to these a few species can be enumerated as belonging to all
or nearly all of the Lower Silurian rocks:

Streptelasma corniculum, Hall. Bellerophon bilobatus, Sowerby.

Orthis testudinaria, Dalman (vane- Murchisonia gracilis, Hall.
ties). ■ Murchisonia milleri, Hall.

The Devonian.

Localities. — Locks of this age are found in Mower county at Austin and
Leroy and eastward from Grand Meadow; and in Fillmore county at
Spring Valley and in the southwestern corner in several exposures of a
porous crumbling rock. This formation doubtless underlies all the ter-
ritory between the points named.

Structural Characters. — In its lower layers the Devonian is a medium
grained siliceous limestone. Near Austin it is gray in color. It has a
very harsh feel. It stains readily when exposed, either at the surface or
along its joints, to atmosphere and moisture, becoming dirty brown in
color or, as at Spring Valley, of a yellowish tint. It is usually quite
massive, breaking into irregular blocks when quarried. In some locali-
ties it is quite porous, due in part to the removal of some of its mineral
matter and in part to the presence of large numbers of casts of some half
dozen fossil species.*

Lithologic Characters. — A medium texture, a granular condition, and
in places a crystalline or a semi-crystalline character prevails. So far as
the specimens at hand have been examined, they lack the rhombohe-
dral form of grain so predominant in the upper Cambrian and Lower
Silurian. This fact is doubtless due to the compacter condition of these
and the additional fact, to which the rocks everywhere bear evidence,
that they are far less altered than are those of the two groups named.

Paleontology. — The fossils of the Minnesota Devonian are few and
poorly preserved. Casts of Atrypa reticularis, Hall, Spirifera pennata,
Hall, and other brachiopods not yet determined occur, together with
several gasteropoda. Heliophyllum halli and Cyathophyllum (sp.?) have
been found inthedrifl of Mower comity. Many bowlders of a Devonian
coralline limestone are picked up around Austin, and they, if searched,
would no doubt disclose several species.

*Some details not here mentioned can be found in the Geologj of Minnesota, Final Report, vol.
i, 1884, pp. 303, 367.

368 hall and sardeson — paleozoic formations of minnesota.

Summary of the Stratigraphy.

The following summary of thicknesses and leading lithological charac-
ters is given on the determinations of several authorities. The larger
number are from measurements and determinations by the writers.

Devonian

f Galena

Lower

Silurian.

Upper

( anibrian

.Not subdivided limestone and shale . . 10-

,-,. • • i Wykoff limestone 501

uinclnnau \ Maquoketa shale and limestone .. 20 i

Maclurea limestone 50

TAngulasma.. .limestone 20

( 'amarella. . . shaly limestone 30

Orthisina calcareous shale 20

Trenton [ Zygospira . . . .shale 8

I Fucoid shale 20

T . j Stictopora . . . .shale HO

Sticloporella. .limestone and shale . 10

Blue limestone 12

Buff limestone 15

Saint Peter. . Not subdivided sandstone 75-

f Upper Shakopee dolomite 10-

| Elevator B (Richmond I sandstone

I Magnesian J Lower Shakopee dolomite 75-

Jordan sandstone 75-

Saint Lawrence dolomites and shales. 30-

Feet.

15
70

120

164
65

20
L75
21 II i
213

[Potsdam . . . .Not subdivided sandstones and shales 0- 1,300

Total thickness of Paleozoic strata in Minnesota 560- 2,437

EXPLANATION OF PLATES 11 AND 12.

Plate 11. — Paleozoic Rocks of Minnesota.

Figure 1. — Basal conglomerate of the Potsdam at Taylors Falls ; the bowlders are

diabase from contiguous masses of that rock.
Figure 2. — Contact of Trenton limestone and Saint Peter sandstone at Minneapolis

in the gorge of the Mississippi river between the Washington avenue

bridge and the State university campus.

Plate 12. — Tnix Sections of Minnesota Paleozoic Rocks.

Figure 1. — Dolomite, middle Magnesian, Hastings; rhombohedral character shown

in a closely crystalline rock. X 70.

Figun 2. — Dolomite, Magnesian series, Mankato; rhoinbohedra with granular cen-
ters and transparent rims. X 70.

Figure 3. — Dolomite, Magnesian series, Frontenac old quarry; the arrangement of
infiltrated coloring matter produces a pseudo-oolitic structure. X 34.

Figure 4. — Siliceous oolite, upper Shakopee (fragment found at ( Htawal ; centers of
spheres show enlargement of rounded quartz grains, i. < ., crystal frag-
ments with subsequent enlargement through deposition of micro-
crystalline silica. The lines show the direction of extinction.

Figun 5. — From a shaly band in the buff limestone, Minneapolis ; under crossed
nicols to show rhombohedral outlines of the grains.

Figun 6. — Maquoketa limestone, slightly magnified ; showing mottling character-
istic of the rock in typical Minnesota localities.

BULL. GEOL SOC AM

1891 PL !I

HaWC

'**TI«" '••"-'. v

*< w

-> — ,

V**-' "^

&!*£

<~>:^ >JK

* * ;

•' ;».J

^H.

FIG. 1. — BASAL CONGLOMERATE OF THE POTSDAM.

FIG 2 —CONTACT OF THE TRENTON AND ST PETER

PALEOZOIC ROCKS OF MINNESOTA.

BULL. GEOL. SOC. AM.

VOL. 3, 1891. PL. \2

: - , •

■ ■ .

• i • :

fc L<W

...

■ ;

Thin S ' oi linnesota «leozoic Rocks.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 369-394

GEOLOGY OF THE TAYLORVILLE REGION OF CALIFORNIA

J. S. DILLER

OF THE UNITED STATES GEOLOGICAL SURVEY, WASHINGTON, D. C.

ROCHESTER
PUBLISHED BY THE SOCIETY

• li i.v, 1892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

VOL. 3, PP. 369-394 JULY 15, 1892

GEOLOGY OF THE TAYLORVILLE REGION OF CALIFORNIA.

BY J. S. DILLEE, OF THE UNITED STATES GEOLOGICAL SURVEY,

WASHINGTON, D. C.

( Read Injure the Society December 29, 1891?)

< '< >NTENTS.

Page.

Part I — The Geologic Column 370

Introduction 370

Reconnoissance of the California Survey 370

Earlier Explorations of the United States Geological Survey ."-71

Topography of the Taylorville Region 371

Formations of the Taylorville Region .' . . 371

Sedimentary Formations 371

Eruptive Rocks 376

Part II — Structure 377

Introduction 377

Unconformities 378

Trias-< larhoniferous Unconformity 378

Jura-Trias Unconformity 379

Neocene-Jura Unconformity 382

Pleistocene-Neocene Unconformity 383

Deformation ;>s'

Structure of .Mount Jura ' :;s I

( reneral Structure ;;s~

( iellesee Anticlinal 388

Northern A rm Synclinal 389

Grizzly Anticlinal 390

Taylorvilli Faull 391

QQQ

Siimmarv ■

•■in. fi Koi,. s,„ . \m.. Vol :. I*''!

370 J. S. DILLER — GEOLOGY OF THE TAYLORVILLE REGION.

Part I — The Geologic Column.

INTRODUCTION.

Reconnoissance of the California Survey. — The Taylorville region of
Plumas county. California, lies in the Sierra Nevada immediately north
of the fortieth parallel. Reconnoitering parties of the ( 'alit'ornia geologi-
cal survey passed through the region in 1861 and 1863* and observed
slates and sandstones, sometimes but little metamorphosed, also hard
lava and granitic masses, and reported that " This part of the country is
principally occupied by the metamorphic rocks over an area of about
thirty miles in diameter." It is "Almost entirely surrounded by vol-
canic materials, the great lava streams which have come down from
Lassen peak on the north and Pilot peak on the south uniting with the
volcanic crest of the Sierra so as to cover the slates around three-quarters
of the circumference of the circle." The state survey party in 1863 con-
sisted of Messrs Brewer and King, who made two very important discov-
eries of fossils, the first near Mormon station, in the canyon about midway
on the road from Indian to Genesee valley, where a considerable number
of specimens of various genera and species were obtained. They were
found principally on the spurs of rocks coming down from the north
and in the canyons between them. According to Professor Whitney, the
rock is a rather tine grained metamorphic sandstone, and portions of
it are of a deep red color, resembling in appearance much of the Old
Red or Devonian sandstone in England and on the continent. In places
it is so much changed that the fossils have become nearly or even quite
obliterated, hut a number of species were obtained ina sufficiently good
state of preservation to be determined. The specimens collected were
referred to Mr. Meek for examination, and were considered by him to be
almost certainly of Jurassic age.f

The second important locality of fossils discovered by Brewer and King-
in this region is on the northern side of < renesee valley, between the main
belt of limestone and the granite. At this point there is a limited patch
of calcareous slates containing quite a number of fossils. Some of them
are very well preserved. Professor Whitney says these fossils belong to
the Triassic series and prove clearly the existence at this point of the
same formation which is so well developed in the Humboldt mining

♦Geological Survey of California, vol. i. 1865, p. 307 The explorations were made by Mr.Ashburner
in 1861 ami by Messrs Brewer ami King in 1863, under the direction oi Professor Whitney, state
geologist. The place called " Elizabethtown " in the above report is supposed to have i n Tay-
lorville, as it i< on the waj to Genesee valley, aboui eleven miles from Quincy, from which it is
separated by a prominent i noun lain. Elizabethtown was much nearer Quincy.

f Ibid., p. 308.

SOUKCES OF INFORMATION. 371

region in Nevada, and also at Washoe, and which we have abundant
evidence to prove extends over a vast area on the Pacific coast. *

Earlier Explorations of the United States Geological Survey. — The writer's
first excursion through this region was made in 1885, and the results
appeared in the United States Geological Survey Bulletin number 33
and in the 8th Annual Report of the Director of the United States Geo-
logical Survey, pages 401-432 ; but the detailed study of the region was
not systematically undertaken until 1890.

In the meantime the region was visited on different occasions by
Mr. I. C. Russell, Professor Hyatt, Mr. II. W. Turner, and Dr. Cooper
( lurtice. The extensive collections made in 1887 by Professor Hyatt and
Mr. Russell, who spent several weeks in the region, were obtained chiefly
from two horizons in the Jura and in the Trias ; but since that time, in
L890 and 1891, Professor -Hyatt has spent several months with me in the
field and made still larger collections from all the horizons in the Jura
and Trias, as well as from a number of older formations. Too great
praise cannot be given him for the assistance his paleontologic studies
in tie- Held have rendered me in working out the structure of tins com-
plicated region. Dr. Curtice was in the region nearly three weeks in 1890,
and discovered a number of new fossiliferous rocks. From Ins collections
Mr. Walcott determined the presence of the Silurian and Carboniferous,
while Professor Hyatt recognized a new horizon in the Jura and the
paleobotanists identified certain slates as Mesozoic.

TOPOGRAPHY OF THE TAYLORVILLE REGION.

The Taylorville region, as referred to in this paper, embraces an area
about 12 miles in Length, from northeast to southwest, and 6 miles in
width.

To the northeast the region is limited by Keith' rock and the divide at
the head of llosselkus creek-; to the southwest by Grizzly mountain,
Hough peak, and Arlington heights, extending to American valley and
Spanish creek. .Mount Jura, so named on account of the Jurassic age of
the rocks it contains, lie- near the center, directly between Taylorville
and Genesee. Other important localities referred to are Foreman and
Peters ravines, which join (he northern arm of Indian valley from the
east : Hinchman ravine, on the eastern slope of mount Jura, and Hornfels
point . immediately north of ( ieiiesce valley, opposite the school-house.

FORMATIONS OF THE TA YLORVILLE REGIOA

Sedimentary Formations. — The accompanying table gives a summary of
the geologic components of the Taylorville region. Thr< f the greal

- • also "Auriferous Gravels of the Sierra Nevada of California ' (Memoirs Mus,
' on,].. Zool, .ii II • • vol. vi) 1879, pp. 39 and W,

:!7:i

J. S. DILLER GEOLOGY OF THE TAYLORVILLE REGION.

groups are represented — the Cenozoic, Mesozoic and Paleozoic, — and of
these there are members in the Pleistocene, Neocene, Jura-Trias, Car-
boniferous and Silurian systems, belonging in a number of eases to well
defined series.

Gf sedimentary formations there are within the region at least eighteen,
embracing alluvium, glacial deposits, auriferous gravels, volcanic tuff,
limestone, conglomerate, sandstone, quartzite and slates ; six of these
are probably Paleozoic, nine are Mesozoic, and three Cenozoic.

Geologic Column of the Taylorville Region.

Group.

i izoie

Mesozoic ...

a
It
((

Paleozoic ....

(?)

System.

Pleistocene.

Neocene

.1 ur.'i (upper)

" (middle)...

(lower)....
Tria 3 ( upper) ....

" (?)

(upper)....

< larboniferous .

Silurian (?)..
(*?')"

(?)
(?)

Series

Miocene....
i lorallian ...
< lallovian..
Ini. ( lolite.

Upper Lias (?).,
Rhsetic (?)

Lower Karnic.
1 rpper Noric...

Niagara.

Sedimentary formations.

Valley alluvium.
Glacial moraines.

Johnson grave] (auriferous)

Hinchman tutf

Bicknell sandstone

Mormon sandstone

Thompson limestone..

Hard grave sandstone

Foreman beds

Trail beds

Hosselkus limestone

I sl:lt"s [Monotisbed J

Robinson beds

Shoo Fly beds

Arlington beds

Taylorville slates

Montgomery limestone

Grizzly quartzite

0) w

a a)
M 8

500

.'i. ii i

10-30

450

1,600

2,900

200

1,150

8,600
5,700
1,800
10-60

4ui I

24,530

The valley alluvium lias been deposited by Indian creek and its trib-
utaries and tills Indian and Genesee valleys.

Glacial moraines are found on the slopes of Grizzly mountain, espe-
cially beneath Tower rock, where they reach nearly to Little Grizzly
creek. A short distance northeast of Kettle cock a moraine forms the
embankment containing Taylor lake.

The Johnson gravels are auriferous and have been mined at the Tay-
lor and Pealc diggings and at the head of Mountain meadows, where
they have an altitude ranging from 5,000 to 5,600 feet, and contain the
remains of Miocene plants.* Mr. Turnery has traced these gravels south
of the fortieth parallel, through the Cascade mine to the vicinity of
Haskell peak, where they have an elevation of 7,000 feet. The south-
erly inclination of the pebbles, the northerly slope of the deposits, and

Eighth Annual Reporl of the 1 lire. 'tin- of the (". S. Geological Survey, part i. L889, pp. 401-432.
t Bull. Phil. Sue. ul' Washington D. C vol. xi, L892, \>. 406.

EARLY MESOZOIC FORMATIONS. 616

the distribution of pebbles containing Jurassic fossils afford strong evi-
dence that the stream by which the gravels were laid down fiowed'frorn
the vicinity of Haskell peak northwardly across Genesee valley and the
northern arm of Indian valley to the Mountain meadows.

There are five formations well exposed on mount Jura. These are the
Hinchman tuff, Bicknell sandstone. .Mormon sandstone. Thompson lime-
stone and Hardgrave sandstone. They all contain an abundance of
fossils, which Professor Hyatt regards as undoubtedly Jurassic. The
Hinchman tuff is a greenish or gray sandrock composed in many places
of lapilli. The Bicknell sandstone is light gray or bluish gray and
sometimes tufaceous above. Its areal relation to the Hinchman tuff has
not been satisfactorily determined. They appear to grade into each
other, and yet they can be separated both on stratigraphic and paleon-
tologic grounds. The Hinchman tuff from both points of view is sup-
posed to be the younger. Both formations are well exposed in Hinch-
man ravine. As may he seen in Professor Hyatt's paper* they are
certainly younger than the other three Jurassic formations and belong
to the upper Jura.

The Mormon sandstone is a line grained, compact, gray fossiliferous
sandstone containing several small beds of conglomerate. It is best ex-
posed on the spurs of mount Jura above Donnerwirth's, at an elevation
of about 4,400 feet. According to Professor Hyatt its fauna belongs to
the middle Jura.

The Thompson limestone is gray above and red and impure below.
Near Thompson's it is burned for lime, but its best exposure is between
Thompson's and the summit of mount Jura, at an elevation of about
l,7<>(> feet. Its position everywhere appears to clearly indicate that it
lies between the Mormon and I [ardgrave sandstones. According to Pro-
fessor Hyatt, its fossils tend to show that it may be younger than the
Mormon sandston

The I [ardgrave sandstone is the red rock of Mormon canyon from which
Brewerand King collected fossils in 1863. Accordingto Professor Hyatt
this is the oldesl formation of the Jurassic system in tin' Taylorville
region, and should he classed as upper Trias.

The Foreman beds are well exposed on the grade of the Lucky S
mine road. They contain slates and sandstone-:, besides several l>ed> of
conglomerate. Near Foreman's Mr. Curtice, in L890. collected from the
slates a few plant remains. Mr. E.G. Paul has since added Largely to

l liia volun

tit' I that all the limesti among the metamorphic rocks of th< Sii Nevndu

■ Carboniferous age (U. S irv. Bull. no. 33, p. 21), bul ii is now known thai Jurassie,

Triusaic and Silurian, as well a- Carboniferous, limesto ir in thai region,

374 J. S. DILLEE — GEOLOGY OF THE TAYLORVILLE REGION.

the collection. Professor Fontaine, who studied the collection, reports
that it contains Equisetum mumteri, Podozamites or Pterophyllum, and three
small ferns, besides Acustichides princeps and Lagenopteris or Cheiropteris.
According to this paleontologist, in whose report the plants are described
in some detail, " They are clearly Mesozoic and most probably Rhsetic in
age. *

The Hosselkus limestone is well exposed where burned for lime and
near the Cosmopolitan mine, on the divide between Genesee valley and
Hosselkus creek. It contains numerous remains of the genus Arcestes,
with a few other fossils, besides abundant pentagonal crinoid stems.
Although there are some round crinoid stems present, the preponder-
ance of pentagonal ones, in connection with. Arcestes, furnishes a ready
means of distinguishing this upper Triassic limestone from those of
Jurassic, Silurian or Carboniferous age. It is one of the most important
formations of the Taylorville region, and has been recognized elsewhere
at numerous outcrops between Spanish ranch and Prattville and at many
other points far to the northwestward, even beyond Pit river, in the
Klamath mountains. t

The Swearinger slates are dark and calcareous, with a thin blue lime-
stone and some siliceous layers. They occur just above Swearinger's
house, on the northern side of Genesee valley, and include the Monotis
bed. Rhabdoceras limestone and Halobia slates of Hyatt. They are all
upper Triassic and rest directly and unconformably upon the Carbon-
iferous.

The Trail beds, which lie farther northeastward, have not furnished
a sufficient number of characteristic fossils to determine their age. On
structural grounds, however, they also are regarded as Triassic, and
probably newer than the Hosselkus limestone.

The Robinson beds contain slates, conglomerate, tuff" and sandstone,
of which the last two are the most important. The sandstone is a pur-
plish rock of great variability. One-fourth of a mile south 50° west of
Robinson's, in Genesee valley, it becomes for a short distance an arena-
ceous limestone. This calcareous portion was discovered by Curtice and
has yielded an abundance of Carboniferous fossils. The material of which
it is composed is chiefly volcanic, and close by the locality just men-
tioned it passes into a well marked tuff. The latter sometimes to the
naked eye closely resembles the porphyritic eruptive with which it is

♦ Letter of December 8, 1891.

j-The name Klamath mountains was first used by Powell (lecture before 1 1 1 < - National Geographic
Society, February 17, 1888, not published) to designate the topographic province in northwestern
California and southwestern < iregon in which the Sierra Nevada, ' lascade and < loast ranges meet. It
embraces tie' mountains locally known near the coast, between the 40th and 4 It li parallels, as Yallo
Bailey, Bully Choop, Pil River, Mail.].'. Trinity, South Fork, Scott, Eddy, Salmon, Siskiyou. Rogue
River, Umpqua and Calapooya mountains.

THE CARBONIFEROUS FAUNA. 375

associated. In some cases it can be distinguished from the porphyritic
eruptive only by the presence of fossils.

The following is a list of the forms identified by Mr. Walcott* from
the calcareous and tufaceous portions of the Robinson beds at the above
localities :

Campophyllum (f). Streptorhynchus crenistria.

Favosites. Productus semin ticulatus.

Archseocidaris. Crinoids.

Fenestella, 2 sp. undet. Productus punctatus ( ?).

Spirifera lineata. Meekella, like striaio-costata, Cox.

Spirifera camerata. Rhynchonella, sp. undet.

Aviculopecten, 2 sp. ■ Aviculopecten inter lineatus.

Myalina, of subquadrata type. Edmondia, sp. undet.
Pleurotomaria, sp. (?).

Microscopic markings of Favosites have been found common in the
sandstone and can he used occasionally in identifying it when all other
fossils fail.

IAthostrotion is an abundant and characteristic form in the Carbon-
iferous limestone at a number of points northwest of the Taylorville
region. The absence of this form among the Carboniferous fossils of
Genesee valley led me to suspect that there are two fossiliferous horizons
in the Carboniferous of northern California, of which the limestone con-
taining IAthostrotion is the older and the Robinson beds of Genesee
the younger. In answer to my .pustion. Mr. Walcott replied that " Two
horizons appear to be represented in the Carboniferous fauna. The
Lower is at the locality west of Bass ranch, near Pit river: also south
of Longville, on crest of Mosquito and Yellow creeks. A somewhat
higher zone is indicated by the collection from southwest of Robinson's,
Genesee valley, and the Little Grizzly locality on the Cascade Gravel
Mine road, in Plumas county. The collections do not clearly define the
lower and upper Carboniferous zones of the Mississippi valley, but they
suggesl t rial they are present."

The Shoo Fly beds include a lime-tone which crops out on Clear creek .
about two miles southeast of Shoo Fly bridge. It contains traces of
crinoid stems, but they are not sufficient to determine positively whether
the limestone is Paleozoic or Mesozoic. On structural grounds, it is
probably either Triassic or Carboniferous, perhaps with a sligh.1 presump-
tion in favor of the hitter.

The Arlington beds, which form Hough peak and Arlington heights,

* Reporl rendered I >< ceml

o —

37G J. S. DILLEK — GEOLOGY OF THE TAYLORVILLE REGION.

are slates and sandstone with traces of conglomerate. None of these
formations have yielded fossils. Some of them arc but little altered. As
they lie beneath the Shoo Fly beds at one end and are associated with
Silurian slates at the other, they are regarded as probably belonging to
the upper Paleozoic

The Taylorville slates and the Grizzly quaftzites adjoin the Mont-
gomery limestone, which is well exposed along Montgomery creek and
the crest of Grizzly mountain. In collections made at these two localities
by Mr. Curtice. Mr. Paul and myself, Mr. Walcott * identified the follow-
ing forms :

Crinoid stems. Heliolites.

Stromatopora , sp. (?) Halysites catenulatus.

Zaphrentis. Orthis, of the type of 0. flabellum.

Syri7igapora,like S. serpens. Ormoct ras (Siphuncles of)

According to Mr. Walcott these fossils are undoubtedly Silurian and
" Represent the Niagara horizon of the Mississippi valley and Appalachian
provinces.'"

Eruptive Rocks. — A large part of the Taylorville region is occupied by
eruptives, of which there is a great variety, not only in chemical composi-
tion and degree of crystallization, but also in manner and time of erup-
tion. There are at least seventeen distinct masses of various eruptives
distributed with considerable regularity throughout the whole region.

On the northern side of Genesee valley the diorite has greatly altered
the Triassic rocks along its contact. It has converted large masses of
them into hornfels. Some of the quartz porphyries or porphyrites may
he of early Paleozoic eruption. The porphyrite a short distance south-
west of Robinson's certainly dates from the Carboniferous, and during
the Trias there were great eruptions of basic lavas. Large masses in
mount Jura were extruded at the close of the Jurassic, and since the
middle Neocene volcanic activity has played an important role in the
geology of that region.

It is evident from what has been said concerning the eruptives of the
Taylorville region that igneous activity did not make its first appearance
there suddenly in a later geologic period, as we are apt to suppose, but
that, as in British Columbia, it began far hack in the Paleozoic and con-
tinued with many interruptions almost to the present. f

♦Report rendered December 8, 1891.

IS'-.- I i-eology of British Columbia, by George M. Dawson (Geol. Mag., dec. ii, vol. viii, April and
May. 1881, p. 17); see also Later Phys. Geol. oi the Rocky Mountain Region of Canada, with special
reference to changes of elevation and the history of the Glacial Period (Trans. Roy. Soc. of Canada,
vol. viii, sec. -i. lN'.m. p. 6) by the same author.

ATTITUDE OF THE STRATA.

o-?

-.i

5 5

g >

c3 ^

"'- 0

03 ^.

> ~

g &H

# 1

;- eo

t: i— i

w ■•

r-s

, i

x ^

-. 0

0 I'

X ^

i <

= ,-

5»

- -

■/.

— 7,

2 i

-to

J3 £

^ _>.

I- o

"*J

.» —

'- 7-

"■C

o ||

<^»

% "*

y '

r 'r

^ —

3 z

—

§ .,-,

•* 2

.- ii

i --

— —

: ..

/. i

T3 z

= c

:>ns

- -- ■<

pa = "£

i *

• a

< -.

— x-

t I a

~ —

Part II — Structure.

IXTRODUCTIO.X.

In the first part of this paper the geo-
logic formations of the Taylorville region
were briefly discussed, so far as their com-
position is concerned. It is now proposed
to consider their geologic structure.

One section 17 miles in length, and four
smaller parallel sections, varying in length
from three-fourths of a mile to one and
one-half miles, were carefully measured
with atape. The thicknesses of the forma-
tions determined by these measurements
are given in the tabular view i >f the geologic
column on page 372, and the structure is
indicated in the accompanying figures.

The long section (figure 1) throughout
its whole extent was measured almost con-
tinuously in the direction north 70° 30'
east. Beginning on the southwest at an
elevation of 3,100 feet on Spanish creek,
it crosses Hough peak at 7,254 feet, and
reaches Indian creek, one and one-halt
miles above Taylorville, at an altitude of
3,500 feet. Continuing in thesame course,
it crosses mount Jura at 6,000 feet about
one-third of a mile south of the summit.
The upper portion of 1 1 ineliman ravine
and other small ravines are crossed to
reach Hosselkus creek, two and three-
fourth miles above Genesee, at an elevation
of t,050 feet. From thence,a1 an elevation

of 6,500 feet, it passe- oVef the northern
portion of Bornfels point, and skirts along
the top of the southern slope of the monu-

tain. whose summit is three miles directly
north of Flournoy's.

The strike of the n.eks throughout the
region is north 5° to 65° west, and the dip,

I.I Bum.. i . -■" . Am., Vol. :;

378 J. S, DILLER — G1C0L0GY OF THE TAYLORVILLK REGION.

with rare exceptions in the Shoo Fly and Foreman beds, is toward the
southwest at angles varying from 39° to 75°.

It is evident that one of the first problems to solve in analyzing the
Taylorville general section concerns the position of each formation in rela-
tion to those immediately above and below; or, in other words, to deter-
mine the original conformities and unconformities among the sedimentary
rocks involved. This is a difficult task in the Taylorville region, where
the stratified rocks arc frequently penetrated and otherwise associated
with eruptive masses, and all of them save the auriferous gravels and
later formations have been involved in profound foldings and disloca-
tions.

Among the rocks extending from well down in the Silurian to the late
Pleistocene there are four breaks in the conformable superposition of the
strata. These unconformities may be designated respectively by the
horizons between which they occur, as the Neocene-Jura, Jura-Trias,
Trias-Carl >oniferous and Pleistocene-Neocene.

Unconformities.

Trias-Carboniferous Unconformity. — The relation of the Trias to the Car-
boniferous is best exposed on the northern slope of Genesee valley oppo-
site Robinson's, where the accompanying section (figure 2) was measured.

S.W. N. E.

Figure 2.— Section of Genesee Valley near Robinson's.
9 = Foreman beds; 11 = Hosselkus limestone; 12 = Swearinger slates: 13= Robinson beds;
E = Eruptive rocks.

Beginning with the limestone on the left-hand spur where it has been
burned for lime, we find it contains fossils that identify it with the
Hosselkus limestone of the next two spurs to the eastward. This spin-
is made up chiefly of slates in which no fossils have been found. The
first ravine toward the right is cut in the porphyrite, the eastern side of
which is tufaceous and belongs to the Robinson beds. The tuff and cal-
careous sandstone both contain an abundance of Carboniferous fossils,
and in connection with the tufaceous conglomerate which underlies the
sandstone they form the second spur of the section up to an elevation of
4,500 feet. Above that point the spur is composed of Halobia slates
and the Hosselkus limestone as represented in figure 2, and both of these

GEOGRAPHY OF THE TRIASSIC PERIOD. 379

formations contain an abundance ofTriassic fossils. They form an arch
over the spur to both ravines, down which they extend far enough to
appear in the lower section of figure 2. The strike of the Carboniferous
strata on the lower part of the spur carries them directly and uncon-
formably beneath the Triassic arch.

The Carboniferous and Trias arc exposed near together for some dis-
tance along the Genesee anticlinal, but northwest of the divide between
Genesee valley and Hosselkus creek they arc so folded and eroded as
to render their unconformity indistinct.

Mr. King has shown that there was probably an upheaval at the close
of the Carboniferous, making a land area in eastern Nevada, and felt
altogether assured in the belief that the Trias and Carboniferous were
unconformable further westward.*

Professor Hyatt has shown that the Trias of Taylorville is upper Trias,
later than that of the Aspen mountains, Idaho, or of the Star Peak range,
Nevada. The Trias-Carboniferous unconformity, therefore, apparently
represents a rather long time interval. The absence of the earlier Trias
may be taken either as an indication that the northern Sierra region was
a land area during that epoch or that the earlier Trias was eroded before
the deposition of the later Trias. It is not impossible that the earlier
Trias occurs yet undiscovered in the northern Sierra Nevada.

Dr. George M. Dawson reports that the Nicola Triassic rocks rest un-
conformably op the Carboniferous in the southern portion of the interior
of the province of British Columbia.f

Jura-Trias Unconformity. — One and one-half miles southeast of Peters',
in the southwestern branch of the ravine which heads near the Taylor dig-
gings, at an altitude of nearly 5,000 feet, the Mormon sandstone (Jurassic)
may be seen resting directly and unconformably upon the Hosselkus
Limestone (Triassic). Both formations contain their characteristic fossils,
and Professor Hyatt, who visited this locality with me, agrees that there
can be no doubl as to the identification of the rocks concerned. Their
exposed areas are rather small, confined to the central portion of the
ravine, and limited on all sides by eruptives. They have been traced
along the ravine for about one-half mile, with a difference of nearly 1 ,000
feet in the altitudes of the terminal p'ortions.

The angle between the strikes of the two formations is 62°, and their
dips are at right angles to each other. In different portions of the area
the strike varies considerably in direction, hut it is evident near their
contact that t he t rem I of t he Limestone carries it unconformably beneath
the sandstone. Their relation- are indicated in the accompanying

Geological Exploration of the Fortieth Parallel, vol. i, s logy, pp. 249-357.

British Columbia : Geol. Magazine, decade ii, vol, viii, April and May, 1881, p, IT.

;J80 J. S. DILLER GEOLOGY OF THE TAYLORVILLE REGION.

section (figure 3). Those relations may be the result of either uncon-
formable deposition or of displacement, or of both.

The sandstone near the contact is much fractured and the pieces in
in many cases are bounded by slickensides. The fossils, which are well
marked in some cases within a rod of the contact, gradually disappear
in that direction as the slickensides increase. The Mormon sandstone
is not the bottom member of the Jura but the third counting from be-
low upward, the Hardgrave sandstone being lowest and the Thomp-
son limestone next. The absence of the lower beds of the Jura and the
presence of numerous slickensides near the plane of the contact render
it probable that there is displacement at this point. Furthermore, a large
mass of the Triassic slates and sandstones, which are younger than the
Hosselkus limestone, do not appear between it and the Mormon sand-
stone ; but this fact may find its explanation either in the displacement
of the beds or in post-Triassic folding and erosion previous to the uncon-
formable deposition of the Jura. The Mormon sandstone in Peters
ravine lies at least in large part between the Carboniferous and the Trias,
a feature which is forcibly repeated in mount Jura, and is fully described
in a subsequent paragraph. Whatever may have been their relative
position at this place originally, it is evident that great changes have been
wrought in it during the folding of the rock at a later epoch.

N.t.

Piouke 3. — Jura- Trias Un co nfo rm i ty .
6 = Mormon sandstone ; 11 = Hosselkus limestone; 13 = Robinson beds; E = Eruptive rocks.

Strong evidence of an unconformity by deposition between the Jurassic
strata and the older rocks is obtained by a general survey of their areal
relations. In connection with the eruptives associated with them the
Jurassic strata form the whole of mount Jura and, with a few exceptions,
are limited to its slopes. The belt in which they. occur is two and one-
half miles in width, with a length parallel to the strike of about five miles.
Although the Jurassic rocks, full of fossils, are well exposed along the
southern side of the northern arm for one and one-half miles, with a
strike to the northwestward, yet it has not been definitely proven that
any of them appear on the other side of the valley, only a short distance
away.

At the southern base of mount Jura the Jurassic rocks cross Indian
creek to the slope of Grizzly mountain, hut the exposures are small, em-
bracing only detached masses of the Hardgrave sandstone, the Thomp-

EVIDENCE OF UNCONFORMITY. 381

son limestone, and the Mormon sandstone, completely surrounded by
eruptive rocks. The thickness of the Jurassic rocks in mount Jura is
2,000 feet. The occurrence of so large a mass of rocks, the newest of the
scries well exposed for so short a distance, while the associated older
rocks upon the sides extend beyond, tends to show that beneath the Jura
there is an unconformity.

The strongest evidence, however, is found in the occurrence of a large
exposure of the fossiliferous Hosselkus limestone at an elevation of 4.800
feet, on the slope of* 1 rizzly mountain (figure 4), about two miles southwest
of Genesee (Hosselkus1). The strike of the limestone at this point carries
it directly beneath the middle portion of mount Jura, where it is com-
pletely covered up by the unconformably overlying Jurassic rocks.

N.E.

' '' >;: 57T77I^#**'

'ilea.

Figure 4.— Section on northeastern slope of Grizzly Mountain.
9 = p0reman beds; U = Hosselkua limestone; 13 = Robinson beds; L6 = Taylorville slates;
18 = Grizzly quartz; E = Eruptive rocks.

The sedimentary rocks lying immediately west of the Jurassic are the
hon-fossiliferous gray sandstone near Donnerwirth's, the Grizzly quartzite,
and the Montgomery creek limestone. At least one of these is certainly
Silurian, and all are Paleozoic. To the eastward the Jurassic beds are
bounded by the Trias. The presence of rather heavy and coarse con-
glomerates in the Foreman beds, as well, as delicate land plants in the
same series. clearly indicates that the youngest Triassic beds of the Tay-
lorville region were laid down not only in shallow seas bu1 near land.

The dip of the strata, as shown in the long section i figure 1 i, from the
Silurian at the summit of Grizzly on the one band, across the Jurassic
of mount Jura into the Triassic on the other, is uniformly southwest-
ward. The Jurassic is thus folded in between the Paleozoic and the Trias,

382 J. S. DILLER — GEOLOGY OF THE TAYLORVILLE REGION.

a position given to it either by displacement or an original unconformity.
Although the Jurassic system lias been completely overturned and greatly
displaced since its deposition, the character of the movements, so far as
they have been made out, were not such as to explain its position folded
between older strata of different ages, and we are constrained to believe
that there is a marked unconformity at the base of the Jura caused by a
folding of the strata at the close of the Triassic.

A general consideration of the character and distribution of Jurassic
strata and fossils throws some light upon the ancient geography of the
region. Professor Hyatt has shown that in the Jurassic rocks of Taylor-
ville the three great subdivisions, namely, lower, middle and upper
Jurassic, are represented, and that it contains a larger number of frag-
ments of the series of the Jurassic system than any other known locality
in the United States. Fragments of the Jurassic system have been recog-
nized in Montana, Wyoming and the Great basin, as well as in Cali-
fornia. The general scarcity, if not the complete absence, of vertebrate
fossils in the Jurassic rocks of Taylorville indicates, according to Professor
Hyatt, that the faunas lived at some distance from the shores of the
Jurassic continent and in a more exposed oceanic area than those of the
Great basin. He announces the fact also that the remains of Oolitic
ammonites have been occasionally picked up west of the crest of the
Sierra Nevada. It seems evident, therefore, that during a large part, if
not the whole, of the Jurassic period the northern Sierra region was be-
neath the sea. and that the disturbance at the close of the Trias, although
it folded and faulted the rocks, did not produce permanent dry land.
The predominance of sandstones with occasional interbedded conglom-
erates, however, evidence rather shallow Jurassic seas at Taylorville.

According to Dr. Dawson, the disturbance at the close of the Triassic
in British Columbia produced quite different results. He remarks : :::
" Though much remains to be discovered respecting this post-Triassic
epoch of disturbance, it was evidently an important one, and its results
were wide-spread in the Cordilleran region. It is quite possible that it
was accompanied by or resulted in producing a general elevation of this
entire region above the sea level, as no rocks certainly referable to the
Jurassic or next succeeding period have yet been distinctly recognized
either in British Columbia or in its bordering regions."

Neocene-Jura Unconformity. — The Johnson grave] is of fluviatile origin.
Northeast t>\' mount Jura it reposes unconformably upon the upturned
edges of the massive Jurassic and Triassic formations. This uncon-
formity is one of the most conspicuous of the region. It represents a

* Trans. Roy. Soc. of Canada, vol. viii. see. iv, 1890, p. 7. See also paper by «;. F. Becker, Bull.
1. Soc. Am., vol.2, 1890, p. 20

ABSENCE OF CRETACEOUS DEPOSITS. 383

great lapse of time, the records of which arc to be found to the westward
in the deposits bordering chiefly upon the Sacramento valley.

That there was in the northern Sierra Nevada, region an epoch of great
disturbance after the deposition of the Jurassic rocks near Taylorville is
clearly shown by the fact that those rocks are overturned and faulted.'
That the disturbance and elevation occurred immediately at the close
of the Jura is rendered highly probable by the complete absence from
the Taylorville section of any Cretaceous deposits. It is possible that
the Cretaceous, if formerly present in that region, has been completely
removed by the great erosion to which the Sierra Nevada bus been long-
ex posed : but of this view I have not been able to obtain any supporting
evidence.

So far as yet known, on the fortieth parallel the rocks next younger
than the Taylorville Jurassic are the Knoxville beds of the earlier Cre-
taceous. They are widely separated in space, and it is probable that
there was between their periods of deposition a considerable lapse of
time, within which the rocks of the Sierras were greatly deformed I >y <•< im-
pression and raised above the sea; consecmently the shore-line of the
Cretaceous sea scarcely reached the western base of the Sierra Nevada
and laid down its deposits unconformably upon the older rocks. f

In order fully to comprehend what is represented by the Neocene-
Jura unconformity of the Taylorville region it is necessary to consider
the relation of the Johnson gravel to the Cretaceous rocks of the Sacra-
mento valley. These gravels were deposited by a stream flowing into the
Mountain meadows region, where some Miocene plant remains have been
found. It has been shown I that these sandstone and gravel strata
probably conned beneath the lavas of Lassen peak with deposits of the
same age on Little Cow creek, at the northeast corner of the Sacramento
valley. At this last locality the Miocene strata resl unconformably on

the ( !hiC0 beds of the ( 'I'etaceoiis.

Iii the Neocene-Jura unconformity, therefore, we have represented not

only the great time interval between the close of the -Lira and the Mio-
cene, hut also two unconformities, the first, and by far the most conspic-
uous, between the Cretaceous and the Jura and the second between the
( Iretaceoua and the Miocene.

Pleistocene-Neocene Unconformity. — The valley alluvium (Pleistocene)
docs not come in contact with the Johnson gravel, and yet their uncon-
formity, du«' to erosion, is will marked. The valley alluvium was de-

* Hull. Geol. Soc. Am., vol, •_'. p. 206.

fThat the ks of the Sh > iwn rest unconformably ii| the older rocks is

well known. Our knowledge of this unconformity has recently been much extended bj Mr. II W.
Fairbanks in the imi riean Geologist for March, 1892 (vol. ix, pp. 153 I HO

t Eighth \iui. Rept. U. S. Geol. Survey, pt. i, pp. 1 1 > 122.

384 J. S. DILLER — GEOLOGY OF THE TAYLORVILLE REGION.

posited by Indian creek and its tributaries in canyons and valleys cut to
the depth of 2.000 feet directly across the bed of the ancient stream by
which the Johnson gravel was deposited. The character of the fossil
plants found in the auriferous gravels at Mountain meadows and else-
where in the same district, as well as the topography of the region, indi-
cates that the northern end of the Sierra Nevada at the time the John-
son gravel was deposited had a much gentler relief and lower altitude
than at the present time. As already shown.* the region was greatly
affected by a post-Miocene upheaval.

DEFORM A 770 V.

Structure of Mount Jura. — Having considered the four unconformities
or structural breaks which occur in the suite of rocks of the Tavlorville
region, attention may he turned to the structure displayed by the youngest
system, i. c, the Jurassic. We may expect this system to be affected by
the same kind of movements and other changes which took place in the
older strata but, on account of its youth, to have been affected in a less
degree, and therefore in certain respects to furnish better examples for
study.

The strike of the rocks in mount Jura, with comparatively moderate
variation, is northwest and southeast, while the dip is uniformly south-
westward. On the western slope of the mountain the continuity of the
stratified rocks is greatly interrupted by eruptive masses, but the strati-
graphic order of the rocks is clearly defined. Near the base, next to the
siliceous eruptive, occurs the Hardgrave sandstone, followed up the slope
by porphyrite and the Thompson limestone, which dips beneath the
Hardgrave sandstone and overlies the Mormon sandstone. Continuing
up the slope, as shown in the section of mount Jura, we next come to a
zone of porphyrite on which there are a number of small areas of strati-
fied rocks, especially of the Hardgrave sandstone. This is succeeded,
near the summit of the spur where the section crosses, by an acid erup-
tive and the Hardgrave sandstone, which are followed in order down
the eastern slope toward Hinchman ravine by the Thompson limestone,
Mormon sandstone. Bicknell sandstone and Hinchman tuff. This suite
composes the smaller section down the western slope of Hinchman
ravine, figure 5 j but on the north the Thompson limestone and a por-
tion of the Mormon sandstone are replaced by an eruptive. The order
of the stratification on the western and eastern slopes of mount Jura is
the same. In both cases the oldest stratum is on top and the youngesl
at the bottom of the suite, and it is evident that the whole mass has
been overturned.

* U. s. Geol. Surv.. Eighth Ann. Rept . 1686'87, pp. W9-422.

Ill': MOUNT JURA FAULT.

385

Furthermore, as shown in the foregoing section (figure 5) which
crosses mount -I urn approximately perpendicular to the strike, the J lard-

Hinchman ravine

FiauEE 6. — Eastern Slop< of Mount Jura.
I Hinchman tuil : 5 — Bicknell sandstom G Mormon sandstone; 7 Thompson limestone;
8 = Illinium vi' sandstone; E= Eruptive rocks.

grave sandstone, Thompson limestone and Mormon sandstone are re-
peated in exactly the same order on opposite slopes, as represented in
figure •'). Such a repetition ofthe strata can be produced only by faulting.

s.w.

ftformon Canon of
Indian Creek

Mt. Jura

Hi nchman
rav I no

Pioi kjb 6.— Section through Mount Jura.

4 = Hinchman tuff ; 5 = Bicknell sandstone; 6= = Mormon sandstone; 7 Thompson lime
8 Hardgrave sandstone ; 9 Foreman beds; LI = Hosselkus limestone ; E = Eruptive rocks.

We should expect the fault or its attendant phenomena to hi' displayed
on the western 'slope of mount Jura, where the repetition begins, and in
fact we find at that point a number of exposure- deserving special men-
tion.

s.w.

,*-"-5C-

Fioubk 7. -<S I'l'-' a ' ■ nerwirtlCs

• Mormon sandstone; 7 Th pson limesl ; 8 Hardgrave sandstone; E Eruptive

rocks.

On the second prominent spur, which reaches the stage road south of
the Indian village at an elevation of 5,100 feet, an outcrop nearly LOO
fei'i in length is exposed. It is illustrated in figure 7.

LI l-l'.ri i flKOi Soi . \\i.. Vol . ::. 1801.

386 J. S. DILLER GEOLOGY OF THE TAYLOHVILLE REGION.

A rather coarse gray sandstone, with a gentle southwesterly dip, is
found lying unconformably upon more highly inclined red calcareous
beds, which contain a number of small lenticular masses of gray lime-
stone. No fossils were found in this locality in the red beds, but they
are between the porphyrite and the Mormon sandstone, which is full of
fossils: and the red beds themselves on the next spur to the southward
contain Opis and an abundance of the screw-shaped gasteropods which
characterize the Thompson limestone. In the overlying sandstone an
ammonite was found, and from the lithologic character of the rock it is
believed to belong to the upper portion of the Hardgrave sandstone.
Whatever its geologic horizon, its present position is due to displacement
from the southwestward, where the Hardgrave sandstone is exposed.

On the prominent spur which reaches the stage road in the bend by
the narrows, one-third of a mile south of Donnerwirth's, at an elevation
of 4,550 feet, a small mass of Hardgrave sandstone, with its characteristic
fossils, occurs directly upon the Mormon sandstone, equally well defined
by its fossils. The conglomerate near by is the one belonging to the
middle portion of the Mormon sandstone. Figure 8 is a section of the
exposure, and it is evident that the Hardgrave sandstone has beenshoved
into its present position from a short distance southwestward, where it
is well displayed near the base of the mountain.

At a number of points on the western slope of mount Jura, a little
above the elevation of 4,o00 feet, small masses of Hardgrave sandstone
occur, but as they are enveloped by porphyrite it is not so apparent that
they have been faulted into their present position. A short distance
further up the slope there is evidence of the faulting found in the breccia
which underlies the siliceous eruptive. The breccia occurs at a number
of points along the course of the fault. It is composed largely of the
fragments of the superior rock and may he an eruptive, hut a more
plausible explanation attributes its origin to faulting.

The two outcrops noted in figures 7 and 8 are in the line of the general
displacement, which causes a repetition of the oldest three Jurassic for-
mations in mount Jura, and it is desirable to note that the amount of
displacement in the two cases is different. While in the first case the
Hardgrave sandstone is carried over upon the Thompson limestone, in
the second it is carried beyond the Thompson limestone to near the mid-
dle of the Mormon sandstone, indicating that the amount of displacement
in mount Jura is greatest in its southern portion. The same feature is
more forcibly illustrated by the relation of the two masses, each of which
is made up of the three repeated formations in mount Jura. While on
the southern slope of the mountain these are separated by a throw of at
least three-fourths of a mile, on the northern portion the displacement

OVERTHRUST TYPE OF FAULT. 387

is expressed chiefly in the widening of the exposure of the Mormon sand-
stone.

The evidences of faulting observed in the different parts of mount
Jura are not to be considered as indicating so many faults, but rather
different portions of one great fault* If we join together all the sur-
faces along winch faulting has taken place to form one continuous sur-
face, it is evident that such a surface must be greatly warped. Its posi-
tion on the western slope of mount Jura is quite clearly indicated by
the exposures already noted. It first appears at an altitude of 5,100
feet in the one case, and 4,550 feet in the other. At both places the
fault has a gentler dip southwestward than the slope on which it occurs,
so that the fault surface at the points indicated leaves mount Jura in the
direction of the lower slope of mount Grizzly. Above these points the
fault surface is nearly parallel with the slope, but just below the siliceous
eruptive it plunges deep into mount Jura with an easterly dip, along
which the three formations of the western slope of the mountain are
repeated in the same order on the opposite side.

It has been remarked that the throw of the fault in the northern por-
tion of mount Jura is snyill, hut in the southern portion of the moun-
tain it is about three-fourths of a mile. The southeastern portion of
the mountain, which is made up of the whole Jurassic series, has been
shoved far to the eastward, so that the Hinchman tuff laps much further
over upon the Foreman slides in that vicinity than further northward.
Their easterly extension connects directly with the faulting, and we may
consider that the fault, after passing through mount Jura with an easterly
dip. rises to the surface again with westerly inclination between the
Hinchman tuff and the Foreman slates, as shown in the section.

The fault on which the upper and eastern portion of mount Jura has
been displaced is thus shown to he an irregularly curved or undulating
surface, the general position of which is nearly horizontal, with a low in-
clination to the southwestward, and the average hade of the fault is
toward the upthrow. It ia evident also that the overturning of tin;
Jurassic strata has been from the southwest toward the northeast, ami
thai the faulting, which is in the same direction, has taken place subse-
quently but probably in immediate connection with the folding.

(,'i a i ral Structure. < lohsideration of the unconformities of the Taylor-
ville section and of the structure of mount Jura prepares the way for a
closer analysis of the structure of the whole region.

A.8 already stated, the strike of the strata is approximately northwesl

► The curvature of the faull -ml' is indeed con i ile, bul in this it does nol differ from

the major faults of the Scottish Highlands. In mount Jura the relation "t the several parts does
nol appe thai of m minoi i uilts, but rather 'tin >renl portions of the same narrow

zone "i displacemenl .

388 J. S. DILLEE — GEOLOGY OF THE TAYLORVILLE REGION.

and southeast, so that the formations of the different geologic horizons
appear in belts crossing the region in that direction. The long section
represented in figure 1 crosses these belts approximately at right angles,
and shows not only the positions of the strata observed, but also, in sonic
cases, their connection beneath the surface.

It is evident that the strata have been either folded or faulted, or both,
to bring them into their present position, and it is important to determine
at the outset, if possible, the influence of each in developing the general
structure.

A glance at the section of the region shows us that there are two belts
of older strata — one in Grizzly mountain and the other in the vicinity of
Hosselkus creek. These are both flanked on either, side and separated
by belts of younger strata : but all the strata, both older and younger, with
rare exceptions, dip southwestward. This distribution might arise from
either folding or faulting. It so happens, however, that in the north-
eastern belt of older strata the anticlinal structure is evident, and in the
middle area of newer ones the synclinal arrangement is clearly indicated.
There is good reason, therefore, for regarding the two masses of older
formations as brought to the surface by anticlinal folds rather than by
faults; but. as already seen in mount Jura, the folding and overturning
of the strata may have been followed by displacement.

Genesee Anticlinal. — The Genesee anticlinal is best exposed on the
northern slope of Genesee valley, where the Trias is arched unconform-
ably over the Carboniferous, as represented in figure 2 (page 378).

Near the crest of the divide between Hosselkus creek and Genesee val-
ley, not far from Robinson's, where the Hosselkus limestone passes over
to the eastern side of the anticlinal, it disappears on the western side,
its place being taken by a belt of eruptive rocks which borders the anti-
clinal immediately upon the west throughout its whole extent. On the
eastern side, however, close to the axis, the Hosselkus limestone is well
exposed along Hosselkus creek, ascending its western branch to near
the Taylor diggings, u here it is intercepted by eruptive rocks but reap-
pears, as already stated, in the southwestern branch of Peters ravine,
associated with Carboniferous and Jurassic strata.

The eastern arm of the anticlinal is very irregularly limited by eruptives.
Near < ienesee valley it is cut off by the diorite, leaving only a. narrow bell
of the Triassic slates, which are turned up near the contact and converted
into hornfels. Further northward it suddenly expands, near Hornf els
point, into a broad wedge-shaped area of the Trail beds, which are sup-
posed to be Triassic. The area tapers rapidly northwestward under the
encroachment of the eruptives from Kettle Rock mountain, which com-
pletely cut off the Genesee anticlinal on the southern slope of Peters
ravine.

DIFFICULTIES OF CORRELATION. 389

Northern Ann Synclinal. — Southwest of the Genesee anticlinal there is a
broad synclinal of younger formations, extending from the Mormon
canyon of Indian creek to nearly three miles northeast of mount Jura.
The best exposures of the strata it contains, besides those of mount Jura,
are to be found in the eastern branches of the northern arm, especially
in the various gulches of foreman ravine.

The detailed, arrangement of the strata within the synclinal is not easily
discerned. This is due chiefly to two causes: (1) the presence of a large
mass of overturned Jurassic strata, which not only fails clearly to partake
of the synclinal structure hut appears by its unconformity to cover up
other strata the repetition of which might he recognized ; and ( 2) except-
ing the Jurassic strata, the formations exposed within the synclinal are
poor in fossils, so that their correlation is a matter of considerable diffi-
culty.

The central sandstone of the Foreman beds is well exposed in Foreman
ravine, and bounded on both sides by slates which contain occasionally
masses of conglomerate composed chiefly of quartz pebbles. The simi-
larity in the general character of the two bodies of slates adjoining the
central sandstone on opposite sides, taken in connection with the re-
currence at corresponding positions within them of rather peculiar con-
glomerates, tends strongly to indicate that they are the same formation
with synclinal connection beneath the central sandstone, but within the
Foreman beds. In the section (figure 1) the place of the central sand-
stone in the middle of the synclinal is occupied by an eruptive.
Although the Foreman beds appear to have been overturned and the
synclinal closed, so that for the most part the dip is southwestward,
there is a large portion of them near the northern end of mount Jura
that dip northeastward, and it is possible that a part of the original
open synclinal yet remains in that protected locality. A few fossil plants
have been found in a slaty portion of the Foreman beds. They are re-
garded by Professor Fontaine as certainly Mesozoic and most probably
Rhsetic in age. A favorable opportunity has not yet occurred to search
for them in all portions of the slates.

The Ilosselkus limestone on the northeastern side of the synclinal is
covered up through a huge portion of its extent by the eruptives ad-
joining the Foreman beds. It is. however, well exposed in this position
;it the old Lime-kiln on the northern slope of Genesee valley.

It lias been recognized in I he southwestern a no of the synclinal, at ;i n
elevation of 1,800 feet on the slope of Grizzly mountain (see figure L-),

aboul two miles southwest of Ilosselkus. where it is evident that ;i shorl

distance further northward it must be concealed from view beneath the

•Inra.

,7.10 J. S. DILLER — GEOLOGY OF THE TAYLORVILLE REGION.

Grizzly Anticlinal. — The existence of the Grizzly anticlinal is not so
clearly defined as that of the Genesee, for its determination depends
upon the presence of one fossiliferous stratum, viz, the Montgomery lime-
stone (Silurian). The strata immediately adjoining this limestone on
both sides are in general much more ancient looking than those coming
next in order, and if we proceed far enough across the strike in either
direction from the Silurian the first fossiliferous strata met with on hoth
sides are much younger. Toward the northeast we need to proceed
only a short distance, for the Jura, as shown in figures 1 and '.), appears
at the very foot of mount Grizzly; hut in the opposite direction the dis-
tance is much greater. Although the limestone of the Shoo Fly beds
contains a few crinoids, no determinable fossiliferous strata are met with
in that direction before reaching the Hosselkus limestone (Triassic) near
the mouth of Rush creek.

Fnii'RE 9. — Northeastern Slope of Grizzly Mountain.
8 = Hardgrave sandstone; 14 = Shoo Fly beds ('.'): 17 = Montgomery limestone; 18 = Grizzly
quartzite ; E= Eruptive rocks.

The distance from the Silurian to the Hosselkus limestone on the
eastern side of the arch is about two miles, for. as we have shown, it lies
unconformably beneath the middle portion of mount Jura, hut in the
opposite direction the distance is at least eight times as great.

While in the Genesee anticlinal the middle of the arch is clearly de-
fined by the Carboniferous, which is flanked on hoth sides by the
Triassic, in the Grizzly arch the noddle formation is less evident. The
oldest stratum known positively by its fossils is the Montgomery lime-
stone, which appears in the very crest of Grizzly mountain (figure 9).
It dips southwestward , overlying the drizzly quartzite, and is itself
overlain by the Taylorville slates. As the Grizzly quartzite is not the
equivalent of the Taylorville slates, it is evident that the Montgomery
limestone is not the middle formation of the anticlinal. A careful
scrutiny of the folded strata on the measured section does not disclose
any repetition which would locate the middle of the arch.

The crest of a mountain developed by erosion of an overturned anti-
clinal is generally formed of hard strata within the upper or long limb

HORIZON OF THE GRIZZLY QUABTZTTE. 391

of the arch, the middle or lowest stratum of the arch being exposed on
the steeper slope in the direction of the overturning. From this point
of view the oldest formation in the Grizzly anticlinal is apparently the
( rrizzly quartzite.

The older strata in the crest of the Grizzly anticlinal are depressed to
the northward. In the summit of Grizzly mountain just north of the
40th parallel they have an elevation of 7.700 feet. From this point they
gradually sink 4,200 feet in three and a half miles to the bridge across
Indian creek, one-fourth of a mile east of Taylorville, where they pass
beneath Indian valley at an elevation of 3,500 feet.

The western limb of the anticlinal embraces all of the formations lying
between the northern extension of the crest of Grizzly mountain and
Spanish creek. Beginning with the oldest, lying near the middle of the
arch, they occur in the following order: Grizzly quartzite, Montgomery
limestone, Taylorville slates. Arlington beds and Shoo Fly beds, together
having a total thickness of over 16,000 feet.

The eastern limb of the Grizzly anticlinal was much contracted and
obscured by the overturning, and none of the formations occurring in
the western arm save the Hosselkus limestone, which is beyond the sec-
tion, have been recognized on its eastern side. The obscurity is greatly
increased by the presence of the Jura, which reposes on the older strata
unconformably and covers them up. It seems most probable also, as
will be shown in the sequel, that the case is still further complicated by
faulting such as affected mount" Jura.

Taglorville Fault. — The terminal portions of the long section are com-
paratively simple. Its greatest complexity lies near the middle, in the
vicinity of the western base of mount Jura. As seen in considering the
northeastern arm of the Grizzly anticlinal and the southwestern arm of
the adjoining synclinal, this limb, which is an element of both, must he
regarded as involving all the strata of the Taylorville region from the
Silurian to the Jurassic, inclusive, having a total thickness of 24,500
feet. In considering this, however, we should reduce the total amount
by 2,001) feet, the thickness of the Jurassic, which lies upon the older
rocks unconformably, which would leave 22.500 feet for the section from
the Silurian to the Triassic, inclusive. The actual thickness of the rocks,
measured from the Grizzly anticlinal to the middle of the northern arm
synclinal, is only about 9,000 feet, so that 13,500 feet <>f strata have sud-

deilly disappeared from the middle portion of the section.

The structure of mount Jura at once suggests thai the disappearance

of this large body of strata may he due to a profound fault along tin

northeastern slope of Grizzly mountain. The fault which we have found
distinctly marked in mounl Jura leaves its southwestern slope for mount

392 J. S. DILLER — GEOLOGY OF THE TAYLORVILLE REGION.

Grizzly on the opposite side of Indian creek, just where we would expect
the fault to occur. Furthermore, the Jura fault has produced exactly
the same kind of effects, different only in degree from those we seek to
explain.

The fault surface and some of the strata beneath have been exposed
by erosion on the southwestern slope of mount Jura, but the immediate
r< suit of this faulting was to narrow the belt of Triassic exposures and
cover them up to the northeastward of mount Jura by shoving over upon
them the Jurassic formations from the southwestward.

The completely brecciated quartz-porphyry or quartz-porphyrite which
occur- so abundantly on the northeastern slope of mount Grizzly over-
lying the fault was. in many cases at least, brecciated at the time of its
eruption, but in other cases it more closely resembles a fault breccia and
its genesis may then properly be attributed to the displacement.

The position of the fault on the lower slope of Grizzly lias not been
definitely traced out, as it has on the southwestern slope of mount Jura.
It gradually sinks to the northward with the crest of Grizzly, reaching
Indian creek Mime distance above the bridge. Continuing in the same
direction, near Chapman's it cuts off a small portion of the northwestern
corner qf mount Jura ; thence it crosses the northern arm and follows the
eastern slope of the curved ridge between Cook canyon and Indian valley
toward Mountain meadows.

On the western side of the northern arm the quartz-porphyry so
abundant on the slopes of mount Grizzly is shoved far over to the north-
eastward upon the Foreman beds, so that the Jurassic formations, if they
extend northwestward beyond the northern arm, are chiefly or wholly
covered up by the fault. To the southward along the slope of Grizzly
the position of the fault has not been definitely traced.

From the relative positions of the Hosselkus limestone, as seen in the
Long section and further to the westward, we can get some idea of the
amount of displacement in the Taylorville fault. This limestone crops
out about one and one-half miles northeast of the axis of the northern
arm synclinal, so that its position in the other arm of the synclinal would
be underneath the middle portion of mount Jura. The 'strike of this
limestone, at its outcrop on the slope of mount Grizzly southwest of
Genesee, carries it beneath mount Jura near the middle. If, now, the
Shoo Fly limestone is Triassic i Hosselkus), as there is some reason for
supposing, the thickness of the strata between the Hosselkus limestone
and the Silurian on the southwestern side of the Grizzly arch is about
15,70 » feet, and the Silurian should he expected below the fault nearly
five miles southwest of the Hosselkus limestone underlying the middle
of mount Jura. This would make the displacement of the Silurian

EXTENT OF OVERTHRUSTING. 393

limestone about four miles. If the Shoo Fly limestone is Carboniferous
the displacement must be greater. As this determination is based on
estimated distances and uniformity of dip, it can only be considered a
mere approximation. However, in magnitude it is not extraordinary
as compared with the displacement of similar overthrust faults in the
northwestern highlands of Scotland* the Rocky mountains of Canada f
and the southern Appalachians. %

The Taylorville fault, as we have traced it across the northern arm. is
found to have an irregularly undulating surface, with a very low general
inclination southwestward, and is in fact part of the same fault which
affects mount Jura. When we compare the total displacement along the
Taylorville overthrust (about 4 miles) with the maximum faulting ex-
perienced by the overturned strata of mount Jura (three-fourths of a
mile) we find the former exceeds the latter over three miles. This dif-
ference is large and suggestive. While it is possible that the supposed
displacement of the Taylorville fault is too great, yet it is quite improb-
able that it is so small as one mile. The Taylorville fault may have had
its inception in the folding that took place at the close of the Triassic, so
that a lame part of its displacement may be pre-Jurassic.

The Taylorville fault was formerly regarded as a normal fault,§ but
later observations strongly indicate that it is an overthrust. Evidence
has not been found to show positively that there has-been any consider-
able amount of motion along the Taylorville fault within the later
geologic epochs. The Tertiary stream which deposited the Johnson
gravels appears to cross the faidt immediately south of the fortieth par-
allel, and at that point, according to Mr. Turner,|| the " amount of fault-
ing has been comparatively slight."

Summary.

There are in the Taylorville region IX sedimentary formations and 17
eruptive masses. The former have a total thickness of 24,500 feet ; 17,500
feet are probably Paleozoic, and 7,000 feet are Mesozoic.

Among the sedimentary rocks, one horizon in the Silurian, two in the
Carboniferous, three or more in the Trias and five in the Jura have been
delinitelv recognized by fossils.

• "The I Irystalline Bocks of the Scottish Highlands L Geikie, Nature, vol. xxxi, 1881, p. 29 ; also
•■ R< porl "ii tli.> l ;.-.- . - 1 1 r Work of the Geologic Suvvey in t lie North wesl Eighlands oi Scotland:" A.
Geikie, Quart. Jour. 'Geo! 3oc, vol. xliv, 1888, i>. 378.

t" Report on tin- Geologic Structure of a Portion of the Rocky Mountains ; " R. G. McConnell,
Geol, Survey Canada, Lnnual Report for 1886, pari \>.

I 'I'll e Overthrusl Faults of ill- Southern Appalachians; C Willard Hayes, Bull, Geol. Soc. Am.,
vol. J. pp. I ll-l'.l, i.l.-. 2 ni'l 3.

\ V . s. Geol. Survey Bulletin no 33, p L3; .-ii-<> Eighth Ann. Rept. CJ, S, I I. Survey, p. 126.

II. w. Turner; Mohawb Lake Beds: Bull. Phil. Soc. of W tshington, vol. xi, p. 106.

I. Ill I'.i 1 1.. Geoi . Boc. A.m., \ ot, 3, 1891,

304 J. S. DILLER — GEOLOGY OF THE TAYLORVILLE REGION.

Among the eruptives there is great variety. Their extravasation, be-
ginning early in the Paleozoic, recurred vigorously in the Triassic and at
the close of the Jurassic, and. finally, also in the Neocene and Pleistocene.

The dioritic rocks of the region are a portion of the great granitoid
mass of the upper Sierra Nevada, and are evidently eruptive, with well
denned contact phenomena in Triassic formations. Their eruption is
certainly post-Triassic * and may have taken place immediately at its
close or after the deposition of the Jurassic.

There are at least four unconformities in the geologic column of the
Tavlorvillc region. Designated by the horizons between which they
occur, they are as follows: Pleistocene-Neocene, Neocene-Jura. Jura-
Trias, Trias-( !arboniferous.

During the greater part, if not the whole, of the Paleozoic the sea
covered the region now occupied by the northern portion of the Sierra
Nevada.

The great disturbance at the close of the ( larboniferous may have been
accompanied by an uplift, forming land during the early Triassic: hut if so,
it subsided and was ready to receive the deposits of the upper Triassic.

The disturbance at the close of the Triassic formed no land in the north-
ern Sierra region, hut that which closed the Jurassic was accompanied by
a great upheaval, excluding the sea to the western base of the Sierras.

The general structure of the Tavlorvillc region involves a synclinal
and two limiting anticlinals.

After the folds were overturned toward the northeast, the Grizzly anti-
clinal was affected by an overthrust fault in the same direction. The
throw along this fault in the older strata is so much greater than in those
of Jurassic age as to suggest that a large part of the displacement took
place at the close of the Triassic and Avas followed by movement on the
same plane at the close of the Jurassic.

* On this point see also"Notes mi the Early Cretai ns of California and Oregon," by G. F.

Becker: Mull. Geol. Soc. Am., vol. -. p. 20G.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 395-412

JURA AND TRIAS AT TAYLORVILLE, CALIFORNIA

ALPHEUS HYATT

ROCHESTER

PUBLISHED BY THE SOCIETY

.h i.v, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 395-412 July 15, 1892

JURA AND TRIAS AT TAYLORVILLE, CALIFORNIA.

BY ALPHEUS HYATT.

{Rend before the Society December 29, 1891.)
( !< )NTENTS.

Page

Introduction 39o

The Trias ■ 397

I >iscovery 397

Swearinger Slates 397

Monotis Bed 397

Daonella Bed 397

Rliabdoceras Bed ' 398

Halobia Bed 399

Hosselkus Limestone 399

< reneral Remarks 400

The Jura 401

Lower Jura or Lias (Hardgrave Sandstone) 401

Middle Jura or Oolite 403

Thompson Limestone (Opis Bed) 403

Mormon Sandstone (Sphseroceras Bed) 40:!

Tnoceramus Bed 4().i

[Tpper Jura or Malm 400

Bicknell Sandstone I Trigonia Bed) 406

Bicknell Tuff 407

Hinchman Tuff (Stylina Bed) 407

General Remarks 409

Tabular View '. 412

I NTRODUCTION.

The results given in this paper are preliminary, bu1 it will be seen
by those familiar with such researches thai my opinions, although for
obvious reasons here considered as provisional and therefore subject to
revision in final publications, have been based upon abundanl materials.
These consist of four different collections: The first was made by Mr.
I. C. Russell ami by the author and his son in the summer of L 888, and

I.I V Hi i i. .., i , \m.. Voi„ :;. I II '",|

396 A. HYATT — GEOLOGY OF THE TAYLORVILLE REGION.

showed the existence of the Lias-- and Oolite in mount Jura, near Tay-
Lorville, Plumas county, California, and the need of making further
researches in this Locality. The second was gathered by Mr. J. S. Diller
and the author in the summer of 1890, and this, together with a third
collection made during the same season by Dr. Cooper Curtice, demon-
strated the existence of a distinct fauna in the Hinchman tuff. It is
only just to add that Dr. Curtice was the first to find this fauna at the
Locality named by Mr. Diller Curtict cliff. The fourth was collected in
the field season of 1891 by Mr. Diller and the author, assisted by Mr.
Iv C. Paul and .lames Storrs. This enabled us to define the different
faunas more exactly and brought to light, in a locality discovered by the
indefatigable exploration of Mr. Diller, an additional fauna in the Bick-
nell sandstone. The success and accuracy of the results attained in such
a difficult field and in so short a time are due to the exertions of Mr.
Diller, who surveyed the surface minutely, leaving literally not the
smallest outcrop unexamined: and his hearty cooperation and sym-
pathy with the work of the paleontologist cannot be repaid by this
formal public acknowledgment. The author desires also to take this
opportunity to return his thanks to Mr. I. C. Russell for similar favors
during the summer when they were associated at Taylorville and in the
more extended exploration of the known localities of the Jura and Trias
at the west.

So far my experience with geologists has demonstrated that by coopera-
tion the paleontologist gathers larger and better collections in the same
time, being freed from the need of doing strictly geologic work, while the
geologist reaps a reciprocal advantage in being able to devote himsell
more exclusively to his own department. There is also a mutual ex-
change of criticism and information arising from the intimate relations
of the work done in both departments which has a decided influence
on the amount and quality of the results. The time saved is very
considerable, since it frequently happens that a new locality indicated
by a fvw fossils picked up by the geologist or one of his party can be at
once explored and the value of the evidence ascertained on the spot;
whereas had the fossils been taken home for examination, either they
would fail to justify any definite conclusions with regard to the age of
the rock or else he the occasion of another visit to the same place, in-
volving sometimes considerable expenditure in money and time.

.Many of the species are not yet named, hut in all possible cases their
European congeners are cited ; and this is quite sufficient for the pur-
pose- of this preliminary notice, which was written in order that Mr.

* Professor Jules Marcou had in his article "Geologie de la Californie" (Bull. Soc. Geol. de la
France, ser. ::. vol. si, !883, p. 1 1 1 1 stated thai the Hardgrave sandstone vvas Liassie.

OLDER TRIASSIC DEPOSITS. 397

Diller's geologic essay might be read in connection with the paleontol-
ogy, so far as his work and mine cover the same ground.

The Trias.

Discovery. — The abundance and good preservation of the fossils in the
Monotis bed of the Swearinger slates was made known by the survey of
California under J. D. Whitney, and they were accurately described by
Gabb in the first volume on the paleontology of California. The Hard-
grave sandstone was also found by this survey, and some of the fossils
of this bed were described by Meek in the same volume. One cannot
praise too highly the work of these explorers and authors when the great
difficulties under which they labored, both in the field and cabinet, are
taken into consideration. They established all that was desired at that
time, the demonstration of the presence of the Trias and Jura in the
Sierras ; and this primary fact and the publication of the fossils also led
to the explorations of which the results are given in this paper. If these
last are in their turn equally suggestive and useful to our successors, they
will have fulfilled all reasonable anticipations.

Swearinger Slates: Monotis Bed. — The first and oldest fauna of the Trias
was found at the locality made known by the California survey near
Robinson's ranch/1' These slates were filled with shells of Monotis sub-
circularis, Gabb, a species so close to the typical M. salinaria, Schloth.,
that 1 have grave doubts if it be really a distinct species. 80 tar, at least,
1 have failed in finding any differential characteristic.

The fossils of M. subcircularis are closely compressed, and the species
grew in banks, as did its congener in limestones at Hallstatt, though
its habitat must have heen a clay bottom. The Monotis is accom-
panied by Pecten deformis, Gabb, which is, however, not abundant.
Hemientolium (Posidonomya) daytonensis, sp. Gabb,f is an equally rare
species, and Modiola triquaetrseformis is still rarer.

!> lonella Bed. — In the upper part of the same slates and closely under-
lying the limestone there is a fauna differing somewhat from that of the
slates below, J comprising —

Monotis subcircularis, Gabb, rare.
Daonella tenuistriata, n. sp.. rare.

*This or some neighboring establishment was then called Gifford's ranch.

fThis is the typi □ u genus, which I have called Hemientolium. The young until a com-

itively late stage has the straighl hinge line gn en in Gabb's figure (Geol. Surv. Cal., Pal., vol. i,

1864, pi. 6, fig. 32). Subsequentlj tin- anterior hinge I in 1 1 d iv> loped im 1 acute ascending wing

mbling th< anterior win '.uliumcor p Quenst.) of the Jura, but no corresponding

a sion of 1 he posterior h ing i« de^ eloped.

rhi 1- provisionally called the Daom lla bed, bul it is no( ye( positively ascertained tli;>t the
fauna i- separable from thai "i the Rhabdoc* ra, I atone.

398 A. HYATT — GEOLOGY OF THE TAYLORVILLE REGION.

Hemientolium daytonensis, n. g., very rare.
Modiola triqusetrseformis, n. sp.,well represented.
Avicula mucronata, Gabb, common.
Inoceramus (?) gervillioides, n. sp., rare.
/V/7m/ inexpectans, n. sp.. well represented.
Lirao acwfo, n. sp., well represented.

This fauna therefore contains all of the species found in the Monotis
bed below, but Monotis lias become very rare, while Modiola is well rep-
resented. Among the remaining specie-. Daonella alone is peculiar to
this level, and Avicula mucronata is characteristic, 1 icing found here as a
common fossil, while both above and below this it is rare, and in the
limestone it is, as a rule, smaller and of a different variety. Inoceramus
gervilliodes is also characteristic of this level.

Rhabdoceras Bed. — Immediately above the slates is a narrow band of
limestone containing an abundant fauna which, however, could not be
exhaustively explored on account of the fragmentary character and
small extent of the superficial outcrops. It comprises —

Monotis subcirctdaris, Gabb, very rare.

Avicula mucronata, Gabb, very rare.

Pert i a ilt form is, Gabb, very rare.

Pecten lasseni, n. sp.. well represented.

Modiola triqusetrseformis, n. sp., well represented.

Myacites, n. sp.. common.

Nucula tin hi*, n. sp., common.

Lima acuta, n. sp.. well represented.

Li inn. sp. (?), a large, almost smooth cast.

Ostrsea, sp. (?), one imperfect valve.

Inoceramus (?) simplex, n. sp.. rare.

Rhynchonella solitaria, n. sp.

Arcestes californiensis, n. sp., common.

Halorites americanus, rare.

Ammonites ramsaueri, Gabb, rare.

Rhabdoceras russelli* n. sp., rare.

Atractites, sp. (?), well represented.

The fauna, of the limestone differs markedly from that of the upper
slates and still more from the lower slates. It lias all the species men-
tioned as occurring below, but they are all rare except Modiola, Pecten
lasseni&nd Lima acuta. As additions we find to he abundant Myacites
and Nucula, with a Large Lima, an Ostrsea and a Rhynchonella. There arc

♦Dedicated to Mi-. I. C. Russell in memory of our work in the field.

EUROPEAN CORRELATIVES. 899

some cephalopoda ; Arcestes is abundant, and a species of Ha lorites ap-
pears. There is also the remarkable Rhabdoceras, a straight species of
the Triassic ceratitinse representing Bactrites among Devonian goniatitina^
and Baculites among Jurassic and Cretaceous ammonitinse. There is
also one of the two primitive forms of belemnoids, Atractites, which is,
however, represented by two fragments, each exhibiting the phragmocone
and part of the guard.

All of these specie-, from Monotis to the cephalopoda, are forms more
or less characteristic of the younger Trias, and if found in Europe would
unhesitatingly lie considered as belonging to the Noric series. After
having expressed this as a provisional opinion in public, I found that
Mojsisovics, who has done more than any one else to establish the sub-
divisions of the Trias on a sound basis, had already published the same
opinion in considering the fossils described by Gabb in the paleontology
of California.*

Halobia Bed. — Above the Rhabdoceras limestone lie unfossiliferous
quartzites, but to the westward, near the top of the Carboniferous spur
(so called on account of the presence of fossiliferous rocks of that system),
we found a bed of slates containing Halobia occurring in banks as did
the Monotis below on the Triassic spur.

These shells have the large anterior ear as in Halobia rugosa, a charac-
teristic species of the upper Noric and lower Karnic series in the Alps,
according to Mojsisovics, and there are some forms approximating to
Halobia superba of the Karnic. The incoming of Halobia after Daonella,
which occurs only in the upper part of the Mound* bed, suggests that we
have here a fragmentary but parallel history to that in the Alpine Trias
so thoroughly worked out by Mojsisovics. Thus, the Monotis and Rhab-
doceras beds will probably prove to be characteristic fragments of the
Noric series, while the Halobia slates and Hosselkus limestone of Diller
may prove to be passage beds from the Noric to the Karnic series. These
slates contain calcareous portions, and in a, small mass of this kind a
fragmenl of a species of Tropites occurred which was sufficiently well
preserved to show the very peculiar form and similar markings to those
of the well known lower Karnic species, Tropites subbidlatm. This was
accompanied by an Arcestes and fragments of Atractites identical with the
species occurring above in the Hosselkus limestone. It is possible thai
the calcareous slates and their fossils occurred immediately below the
Hosselkus limestone, hut of this there are at present no positive proofs.
Hosselkus Lhnest mc — -Tic Hosselkus limestone occurs above the Halobia
slates on Carboniferous spur, and contains the same forms oi Atractites

i eber Pelecypoden Gatt. Daon tin u, Halobia: Abh. d. k. \t. geol. Beiehsivnst., 1'.. mi. 1874,8 \.

100 A. HYATT — GEOLOGY OF THE TAYLORVILLE REGION.

and Arcestes, together with a Tropites which may be the young of the
species of this genus occurring in the Halobia slates. The forma com-
prise—

1 | Arcestes-phylum of .1. tornati; Noric and Karnic.

" A. galeaii : Noric.

" A. bicarinati; upper Noric and lower Karnic.

•• A. sublabiati : Karnic.
Badiotites, allied to B. eryx, Mojsis. ; upper Noric and lower Karnic.
Juvavites, allied to ./. erlichi, Mojsis. ; upper Noric and lower Karnic
Tropites, may he young of species occurring in Halobia slates; Karnic.
Atractites.

Arcestes (1 ) is very abundant, but whether the other forms are abun-
dant or not it is difficult to say at present. The materials gathered show
that the rock is full of fossils, but these cannot be obtained in any reason-
able time by means of surface work. Besides the species mentioned,
there is a form of Acrochor dicer us, with finer costse than those occurring
in the Muschelkalk, a possible Balatonites, like B. waageni of the Noric.
and some other fragments of ceratitinse, all indicating a fauna rich in
ammonoids, which will some day yield a good harvest to patient work.

General Remarks. — The results of explorations made up to the present
time admit of some general comparisons, which, although by no means
conclusive, are suggestive and interesting.

The Trias of Idaho I Aspen mountains, near Soda springs) has a well
marked Triassic fauna, with fossil cephalopods recognized in Europe by
Mojsisovics, Steinmann and Karpinsky as belonging to the lower part of
the Triassic system, and. after careful re-examination of the fossils, I find
strong grounds for thinking that this opinion is probably correct, This
fauna appears to lie more nearly the equivalent of that of the Werferner
beds of the noddle Buntersandstein of the German Trias than of any
other.

The Trias of the Star Peak range in the Humboldt region, Nevada,
contains an unmistakably younger fauna. Before reading the similar
opinion of Mojsisovics, published in Ins superb work "Die Cephalo-
poden der Mediterranean Trias-Provinz," I had arrived independently
at the same opinion, that this fauna belongs to the Muschelkalk and not
to the younger Saint Cassian stage, as formerly supposed. When the
species are properly published the parallelism with the Muschelkalk will
he readily -ecu. since well preserved cephalopods are abundant.

Idle Trias of Taylorville is quite as interesting as that of the other two
localities, and it is very suggestive that its age, as indicated by the fossils.
is that of the Noric and Karnic series in the upper Trias.

age of the hardgrave sandstone. 401

The Jura.

Lower Jura or Lias ( Hardgrave Sandstone). — The Hardgrave sandstone
contains the remains of a very abundant fauna and the fossils are suffi-
ciently well preserved.

The most abundant species are the following: Pecten acutiplicaius,
Meek, is to he expected wherever this sandstone occurs and can lie called
its characteristic fossil in this region : Entolium meeki is perhaps the next
in abundance and is almost as widespread in distribution ; Pin mi expansa
is not found everywhere, hut it forms banks like Ostrsea or Unio in some
places and is often found associated with the two above named.

The age of the Hardgrave has been determined by cumulative evi-
dence. That it was probably a member of the Lias, as previously stated
by Professor Jules Marcou, became evident after a preliminary examina-
tion of the fossils, but the facts leading to the conclusion that it is more
likely a member of the upper Lias than of the lowest Lias were more
difficult of acquisition. It contains many fossils having affinities with
those of the lowest or infra Lias, and the Modiola and Mytilus might even
have occurred in the uppermost Trias or Rha?tic. On the other hand,
some forms have very close relations to the same genera as they appear
in the Mormon sandstone, or Oolite, of the same locality. Pimm, Ger-
villia, Ctenostreon, Entolium, Trigonia and Cidaris show an assemblage of
upper Lias types. The species of Entolium and Ctenostreon are closely
related to those of the Oolite above, and one species of Trigonia resembles
the young of a species from the Oolite of western Europe. The most
conclusive evidence, however, is furnished by the single well preserved
specimen of Glyphea, which 1 was so fortunate as to find in the typical
locality close to the village of Taylorsville, and the Goniomya, allied to
G. v-scripta, Agassiz.

The II' species exhibited, which were selected from the collections of
the Geological Survey, do not represent the entire fauna. I have still
farther restricted the list given below to those species which are either
characteristic or have been described and figured or can he closely com-
pared with representative European species:

Taylorville, California. Europe.

Mpntlivaultia, n. sp. .(?). M. haimei, chap, el Dewal.j lower

Lias.
Ostrsea, sp. Ostrsea irregularis, Chap, el Dewal. ;

inferior Lias to middle Lias.
Ostrsea, \\. sp. Ostrsea arietis, Quenst.; lower Lias.

Anomia, n. sp. Anomia striattda, Terq. el Piette;

lower Lias.

1:02

A. HYATT — GEOLOGY OF THE TAYLOUVILLE REGION.

Taylorville, < 'alifornia.

Modiola, n. sp.
Mytilus, 11. sp.
Mytiius, n. sp.

Pinna expanse,, n. sp.
Gervillia linearis, n. sp.

t n rvillia giga/ntea, n. sp.
6r< rvillia gigantea, n. sp.

Lima, n. sp.

( 7^ nostreon, n. sp.

Pecten acutiplicatus, Meek. J

Z/im« sinuata,

Lima recticostata, )

Pecten, n. sp.

/'/ (/' //. n. sp.

Entolium meeki, n. sp.

Goniomya, n. sp.
Pholadomya, n. sp.

Pleuromya, n. sp.

Trigonia, n. sp.
Trigonia, n. sp.

f 'idaris, n. sp.

Glyphsea punctata, n. sp.

Europe.
Modiola psilonoti, Quenst. ; lower Lias.
Mytilus psilonoti, Quenst.; lower Lias.
Mytilus lerquemianus, Chap< etDewal. ;

lower Lias.
Pinna hartmanni, Auct. : lower Lias.
Gervillia lanceolata, Quenst.; upper

Tans.
Gervillia aviculoides, Quenst. ; Oolite.
Gervillia betacalcis, Quenst.; middle

Lias.
Lwm nodulosa, Terq. et Piette ; lower

Li;is.
/V///'/ charta, Dum. ; lower Lias.
/,om/ galathea, Dum.; upper Lias.
Lima tuberculata, Dum.; lower Lias.

Z/£m« acuticostata, Schubl.; inferior

Oolite.

Pecten textorius, Goldf. ; Lias and

Oolite.
Pecten dextilis, Miinst. ; Lias and

Oolite.
Pecten demissus, Goldf.; Lias and

Oolite.
Goniomya v-scripta, Ag. ; upper Lias.
Pholadomya ambigua, Sow.: upper

Lias.
Pleuromya striatula, Dum.; upper

Lias.
Trigonia costata, Sow. ; middle Lias.
Trigonia costatula, Lycett; inferior

Oolite.
( 'idaris, Quenst.; upper Lias.
Glyphsea solitaria, Opp.; inferior

Oolite.

1 showed the unique fossil Glyphsea punctata, of which the carapace (with
the exception of the tip of the rostrum) is well preserved, to Professor
Walter Faxon, of the Museum of Comparative Zoology, well known as
an expert carcinologist, and he at once placed it in the Jura under the
name of Glyphsea. G. solitaria, ( >pp., of the lowest < >olite, zone of Trigonia
navis, is not only very close to our American form in the characteristics

MINGLING OF TYPES IN THE HAtlDGRAVK. 40

of the sutures of the carapace, but the surface has the rare sculpturing
of punctation in place of the usual tuberculation found in most species
of this genus, a peculiarity also characteristic of G. punctata. Such forms
as these and the evidently close alliance and probable continuity of the
fauna through migration with that of the Mormon sandstone suggest
that the Hardgrave sandstone should he classed as upper Lias in spite
of the large number of forms which are represented by species occurring
also in the lower and middle Lias in Europe.

The homogeneous character of the rock and the association of fossils
found in the larger masses of it led also to the conclusion that it repre-
sented only one bed in the upper Lias, but such minute researches as
would have established this beyond question were not practicable.

Middle Jura or Oolite: Thompson Limestone {Opis Led). — Mr. Diller's
dose and repeated investigations of the stratigraphy have placed the
Opis bed below the Mormon sandstone in the chronologic series, and
my studies, although they led me to incline to the opinion that the
fauna was younger, have not succeeded in bringing to light any evidence
that can be said to contradict bis conclusions. The presence of a large
form of Nerinea with the columella, showing the typical ridges of the
normal forms of this group, indicate that this limestone is not older than
the inferior Oolite, and if. as seems to be the case, it is older than the
Mormon sandstone it will probably be proved to be a member of the
inferior Oolite.

A large species of Oyy/.s is as abundant in some places as the Nerinea,
and this genus, winch is recorded in Europe as beginning in the Trias, is
usually small throughout the lower and middle -Jura. The only Euro-
pean species approximating to that of this limestone is the Opis paradoxa,
as figured by Buvignier* which occurs in the Corallian of the upper
Jura. A species of Terebratula, apparently identical with the large char-
acteristic species of the Mormon sandstone, also occurs abundantly in
this bed. There are also a number of small gasteropoda and other fos-
sils requiring further investigation.

Mor n Sandstone ( Sphssroceras Bed ). — This bed contains the remains

of a more varied fauna than that of the Hardgrave sandstone, in some
places, especially upon spur 8 of Mr. Diller's map, the fossils arc in ex-
cellent preservation; but in some localities merely superficial work does
not give good results, the rock being apt to be very friable. Here as
elsewhere tic greatesl treasures await resurrection at the hands of those
able to dig deeply into the stony matrix.

It is more difficull to poinl out the characteristic lossils in this bed

Stat. geol., mill., metal, el pal. 'In Depart, tie la Meuse, 1852, pi. 13, figs. 37-42.
I.\ Bi li.. i Soi . Vm., Vol. 3, 1891.

104

A. HYATT — GEOLOGY OF THE TAYLORVILLE REGION.

than in the Hardgrave sandstone Lima dilleri and L. taylorensis, Ctenos-
treon, Trigbnia and Entolium arc ant t<> occur in all the outcrops. So far
as the determination of age is concerned, however, the ammonitinae,
although not abundant, afford the best evidence. These highly special-
ized forms, as has been pointed out by several of the most distinguished
paleontologists, in Europe, must have been extremely sensitive to the
influence of the changes of the surroundings in passing from one geologic
level to another, and have recorded these mutations in their own organi-
zations. Even the encyclopedic Quenstedt continually expresses his
satisfaction in turning from the uncertain indications afforded by the
more generalized structures of other mollusca to the decisive chronologic
evidence usually given by the fossils of this group. The list printed
below contains a series of selected species, hut many forms, especially
among the smaller pelecypoda, which have not yet been studied, are
necessarily omitted :

Taylorville, California.
Terebratula.

Rynchonella, n. sp.

Alectryonia, n. sp.

Modiola subimbricata, Meek, and
also other species of the same
genus similar to this, but hav-
ing shorter and broader shells.

Mytilus, n. sp.

l'iii mi film iformis, n. sp.

I'ti roperna, n. sp.

Europe.

Terebratula perovalis, Sow., as figured
and described by Quenstedt, is
similar, but the American species
has no dwarfed varieties: inferior
Oolite.

Rynchonella quadriplicata, Zeit., as
figured and described by (Quen-
stedt; great Oolite.

Orthis marshii, Goldf.. as figured by
Mor. et Lye. in Oolite Mollusca;
inferior and great Oolite.

Modiola imbricata, Sow., and other
species of Modiola, with heavy
umbonal ridges, occurring in the
inferior and great Oolite.

Mytilus sublsevis, Mor. et Lye, and
other species, having arcuate forms
and heavy umbonal ridges, which
are characteristic of the Oolite.

Pinna cuneata, Phill., as figured by
Mor. et Lye. in Oolite Mollusca ;
inferior Oolite.

Stands between Pteroperna phi mi and
Pteropema costalula, Mor. et Lye;
inferior and great Oolite.

FAUNA OF THE MORMON SANDSTONE.

405

Tayloroille, < 'alifornia.
Gervillia, n. sp.

Gervillia. n. sp.

Lima dilleri, n. sp.
Lima, n. sp.

Lma taylorensis, n. sp.

( 'tenostreon, n. sp.

Pecten, n. sp.

Pholadomya, n. sp.

Trigonia, n. sp.

Trigonia, n. sp.
Belemnites, n. sp.

Sphseroceras, n. sp.
Grammoceras, n. sp.

Grammoceras, n. sp.

Europe.

G< rvillia lanceolata of the upper Lias,
but longer and narrower in pro-
portion, and the posterior wing-
larger. It is in fact a more pro.
gressive form in the same series of
species than Gervillia lanceolata.

Gervillia aviculoides, Sow.: great
Oolite.

Zk'ma cardiiformis, Sow. ; great Oolite.

£/>/w tenuistriata, Miinst. and Goldf. ;
inferior Oolite.

/>////" rigidula, Mor. et Lye.; great
Oolite.

Ctenostreon pectiniformis, Mor. et Lye. ;
inferior and great Oolite.

Licit a disciformis, Schubl. ; inferior
Oolite.

/'< ctew demissics-gingensis, Quenst. ; in-
ferior Oolite.

Pholadomya fidicula, Zeit. ; inferior
Oolite.

Trigonia hemispherica, Lye; inferior
Oolite-.

Trigoniaformosa, Lye. ; inferior Oolite.

Belemnites breviformis, Voltz. ; upper
Lias to inferior Oolite.

Sphseroceras gervilli ; inferior Oolite.

Grammoceras toarcense, as figured by
Buckman; interior Oolite.

Grammoceras leurum, Buekm.; in-
ferior Oolite.

The fossils indicate the former existence of a fauna which can he pro-
visionally considered as belonging to the upper part of the inferior

Oolite.

Tnoceramus Bed. — Emmediately above the Mormon sandstone with its
rich fauna there are strata of a red sandstone containing very few re-
mains ami these usually in poor condition. Three species of fossils were
found in them: a Terebratula, apparently the same as that occurring so
plentifully in the typical Morman sandstone: two fragments of a large

•100 A. HYATT — GEOLOGY OF THE TAYLORVILLE REGION.

species of Tnoceramus) and a fragmenl of an ammonite of the genus Peri-
sphinctes. The Tnoceramus of the Jura is not so large in the Lias as in the
Oolite and these fragments appeared, therefore, to have belonged to
shells al least as old as the Oolite. The specimen of Perisphinctes may
prove to be identical with some species found below. It is probable,
therefore, that this bed belongs, as in fact is indicated by the geology, to
the upper part of the Mormon sandstone. On the other hand, the fact
that one out of the three species was new to the fauna of the Mormon
sandstone justifies a provisional separation under a different title on
biologic "rounds. Even if not sustained by future work, this distinction
will serve a good purpose if it succeed in calling the attention of col-
lectors in the same or other localities to facts that might otherwise escape
t heir notice.

Upper Jura or Malm : Bicknell Sandstone ( Trigonia Bed). — The fauna
of the Bicknell sandstone is not so rich in species as are the Mormon
and Hardgrave sandstones and the Thompson limestone, nor are the fos-
sils so plentiful. The character of the rock in the surface exposures
found by the party made it almost impossible to get out large specimens
in perfect condition. Nevertheless, a sufficient number of molds of sev-
eral large species of Trigonia (T. obliqua and T. plumasensis) and some
well preserved specimens of Gryphasa bononiformis were secured; allot'
which are more or less characteristic of the youngest faunas of the Jura
in Europe.

The remains of the anmionitiiue are fragmentary, but those that were
found certainly indicate a somewhat older fauna than the species above
named. There are a number of the molds of Rhacophyllites with the
internal septa partly preserved, a fragment of a Reineckia, two rather
pool- molds of Macrocephalites (f), and several fragments of Perisphinctes..
These form an association which gives strong support to the provisional
opinion that the faun:! is really synchronous with that of the Callovian,
the oldest fauna of the upper jura, or Malm, in Europe. The specimens
of Chemnitzia are molds of a very large shell, but unluckily do not show
the aperture. The only species in Europe which appears to be a close
ally of this is also from Callovian.

The list below gives a very inadequate idea of the fauna., since none
of the belemnites or animonitinae can he directly compared with Euro-
pean species on account of the need of more perfect specimens and are,
with one exception, not mentioned. There are also a Large Nerinea and
a \\-\\ species of pelecypoda and brachiopoda, which were not considered
important in this preliminary notice;

FAUNA OF THE BICK>NELL SANDSTONE. 4<>7

Taylorville, California. Europe.

Gryphsea bononiformis, n. sp, Ostrsea bononise, Sauv;, as figured by

de Loriol et Pellat ; Portlandian.

Entolium costaium, n. sp.

Oxytoma, n. sp.

Trigonia obliqua, n. sp. Trigonia michelloti, de Lorio] : Port-

landian.

Trigonia plamasensis, n. sp. Tri</<nii<i lusitanica, as figured by

Choffat ; Portlandian.

Trigonia naviformis, n. sp. Trigonia navis; inferior Oolite.

c/iniiiiitziii, n. sp. Chemnitzia atfAteto, d'Orb. ; Corallian.

Rhacophyllites, n. sp.

The group of Trigonia glabrae, to which 77. obliqua belongs reached its
acme in the Portlandian, the species being both rare and comparatively
small in the Lias and inferior Oolite. T. obliqua is of extraordinary size
and shows the incomplete costse of the Portlandian species. The group
of Trigonia to which T. plumasensis belongs is very peculiar in the char-
acteristics of the costa* and the ornamentation of the anal area, and it
has hitherto been represented in Europe only by the unique form. T. lusi-
tanica, found only in the highest Jura of Portugal. Besides these two
large species there is also in T. naviformis an equally large representative
of another peculiar and hitherto unique style of ornamentation. This.
as its name implies, is similar to T. navis* of the inferior Oolite in Ger-
many, a species hitherto considered to be the only representative of a
very distinct group, the Trigonia scaphoidse, and having a pattern of nota-
tion not (bund in any other species (except T. naviformis) and a narrow
chorologic range.

The group of the Trigonia undulata is represented by a species also of
extraordinary size, but the Trigonia clavellatse, the group more largely
represented than any other in the inferior Oolite (if one can judge from
thesingle specimen obtained in (he Bicknell sandstone) is not materially

modi lied.

Bicknell Tuff. — Above the sandstone and in immediate contact with it
is a tuff described by Mr. Diller, which contains in part the same specie-
as the sandstone, and the fossils indicate the same fauna. Nevertheless
it should he noticed that it contained no remains of Ti'igonia, and that
the fauna has not been critically examined.

Ilincliinan Tuff (Stylina Bed). — The presence of the same species of
Rhacophyllites as thai found in the Bicknell sandstone indicates the con-
tinuity of the fauna of this bed with that of the preceding; hut. on the

i lie differences between Hie <»<• are quite sufficient t" separate them as distinct -i i.--. bul

they have the same styie ol i in • specially "ii the anterioi region.

Ins

A. HYATT — GEOLOGY OF THE TAYLORVILLE REGION.

other hand, the absence of Trigonia and the presence of close allies of
Ostrsea bruntrutana and of Pecten suprajurensis, shows that we have as-
cended in time to a younger fauna. The abundance of corals of the
genus Stylina, these being the most widely distributed and characteristic
fossils of the Hinchman tuff, shows that the age is probably that of the
( 'orallian. In Europe these corals are rare in the Oolite, hut reach their
acme in numbers of species and forms in the ( orallian of the upper Jura.
The opinion expressed with regard to the age of the Bicknell sandstone
is greatly strengthened by this fact, and it also adds to the evidence that
the subdivisions of the Jura in North America and in Europe, like those
of the Trias, may be compared much more closely than one would at
first suspect *from the extremely fragmentary records heretofore found in
this country.

The fossils occurred in patches and, although abundant, good speci-
mens were not easilv obtained. The list is as follows :

TaylorvilU .
Grypha n curtici^ n. sp.

Camptonectes bellistriatus, Meek.

< 'hemnitzia.

Rhacophyllites same species as in

the Bicknell sandstone).
Stylina tubulifera.

Stylina subjecta, n. sp.

Stylina alba, n. sp.

SI i/} inn niiiiiifii. 11. sp.

Stylina inteynn dia, n. sp.
Stylina tertia, n. sp.

Europe.

Ostrsea bruntrutana. as figured hv de
Loriol ; Corallian to Portlandian.

Pecten suprajurensis, Buvignier; Kim-
meridgian.

Chemnitzia athleta, d'Orb. ; Coral-
lian.

Stylina tubulifera, Ed. et H. ; Coral-
lian.

Aslrea tubulifera, Goldf. ; ('orallian.

Closely allied to a specimen in
Museum of Comparative Zoology
named S. echinulata, Lm'k. ; Coral-
linn.

Resembles the Cretaceous species
figured by Cold fuss as Astrea gemi-
nala (equal S. geminata, Ed. et H.),
hut septa are not so symmetrical.

Two species of Belemnites and a number of gasteropods, pelecypods
and brachiopods were also found in this bed.

* I dedicate this important species to Dr. Cooper Curtice, the discoverer of this fauna.

HOMOTAXIS OF THE FAUNA. 409

General Remarks. — The discovery of the parallelism between the faunas
of the Jura in India by Waagen, in Australasia by Moore and Etheridge,
and in South America by Bayle and Coquand, Marcou, Gottsche, Stein-
mann, and the author of this paper, makes one more confident in de-
ciphering the somewhat fragmentary remains found in these rocks, since
everywhere homotaxial relations have been found to exist and it has
been discovered that there is plainly parallelism in the evolution of the
faunas on the different continents, enabling one to make close compari-
sons between the different series and often also even between the sul (di-
visions or stages of those series, as has been done provisionally in this
paper.

So far as the paleontologic researches have extended, they show that a
series of fossil faunas exist in the rocks of Mount .Jura, which approxi-
mately represent the three great subdivisions of the Jura, namely, the
lower, middle and .upper Jura ; and these in their general faunal char-
acters and associations of forms are, considering their wide removal from
the European localities, not more distinct than one might very reasonably
have anticipated.

All explorations have hitherto failed in bringing to light any very re-
markable or entirely new types, such as have been found among the
vertebrata on this continent. The general scarcity of the remains of
vertebrates at Taylorville is another notable feature. A few fragments
have been found, and possibly diligent and prolonged special research
might bring to light more specimens and species, but they are not com-
mon, since the explorations, although confined to the surface, were
thorough. Tins fact is applicable to the entire column of the Trias and
•Jura as heretofore explored along the western slopes of the Sierras and
Andes, and it is probable that these faunas lived at some distance from
the shores of the Jurassic continent and in a more open oceanic area
than those of the Rocky mountain region or Europe, a conclusion in
complete accord with the results of geologic research. In making com-
parisons between the Jura of Taylorville and that of Aurora, Wyoming,
near Red buttes on the North Platte, and of the Black hills,* one is
struck first by the fact that the latter were deposited in the same basin,
the species being largely identical, as already demonstrated by Meek;
and then, thai they can lie spoken of together as having the distinctive
characteristics,)!' the fauna of (he Calloyian or ( ).\ fordian in the upper

♦ Localities near N irthside, Bull Lake fork, southeastern [daho, and on Aquarius plateau, I I ill

have fossils apparently of the at 'fauna; but so little has 1 a collected that one cannol sp<

wiili certainty. Campionectet and < >.-h ,i ,<, found al various localities in Utah an. I descril ed bj I 'i .
White in the report on Explorations west ol the 1 00th Meridian (vol, iv, pari t) indicate the presence
of similar frag ni-' of the Callovian or Oxfordian ai other localities in Utah.

410 A. HYATT GEOLOGY OF THE TAYLORVILLE REGION.

Jura of Europe. A fine scries of ammonitinse collected at Aurora, Wyo-
ming, shows the presence of the same species as those occurring at the
Black hills, and other fossils arc also identical. The genera to which they
belong arc all included in the group of the cardioceratidse, under which
name I unite the genera Cardioecras, Cadoceras, Quenstedioceras and Neu-
mayria, all of them being peculiar to the Callovian and Oxfordian in
western Europe and Russia. Although very often confounded with the
amaltheidse of the Lias, these genera have entirely different young forms
and adult characteristics, especially in the sutures, and also have sprung
from different ancestral radicals.

On going a step farther, however, and comparing the species* with
those of the supposed Callovian of mount Jura it becomes evident that
they have no species common to both ; but, on the other hand, Camplo-
nectes bellistriatus and possibly some other pelecypods and brachiopods
are found occurring not in the supposed Callovian, but in the supposed
Corallian of Plumas county. This unexpected result is in accord with
the very distinct faunas of the Bicknell sandstone, or Trigonia bed, and
of the Hinchman tuff, which do not permit us to suppose any very open
or direct connection existed with the upper Jurassic faunas of the Rocky
mountain region, and is in accord with the similar facts observable in
the Oolite.

When attempts are made to compare the Oolite of the Rocky mountain
region with that west of the Sierras, existing information with regard
to the localities is found to be very imperfect. The Oolite certainly seems
to have been found by Dr. Peale near the lower canyon of the Yellow-
stone in Montana, and out of the few fossils described by Dr. White some
are closely similar to these of the inferior Oolite at mount Jura. Modiola
subimbricata is apparently common to both faunas, and some of the species
of Gervillia may la' identical ; but the species of Trigonia are entirely dis-
tinct from those of mount Jura.

Oasteropods and cephalopods have not been noticed in these Oolitic
faunas. While this may be owing to insufficient collecting, it is well
to note the fact; for although the remains of Oolitic ammonites have
been occasionally picked up west of the crests of the Sierra Nevada,
no such finds have thus far occurred cast of that line, so far as known
to me.

The lower Lias, containing characteristic ammonitinse, one species of
which (Amioceras humboldti) was described in my "Genesis of the Arie-
tidse," occurs in the region formerly called the American district, Nevada.

*The entire absence of gasteropoda from these deposits has been noted by Whitfield in his report
on the fossils of the Black hills, and the same may be* said with regard to the marine faunas at
Aurora, Wyoming, and other localities mentioned above.

DISTRIBUTION OF JURASSIC AMMONITES. Ill

probably in the southern portion of the Star Peak range. There are also
fossils in the collection of the mining bureau at San Francisco labeled
as having been gathered in the Santa Fe district, Esmeralda county,
Nevada, and Inyo county, California. These would not be worth men-
tioning were they not reported from places lying in the direction of the
general strike of the Jurassic strata and also in perfect accord with the
presence of Amioceras humboldti. One species is a form of Vermiceras
allied to 1". conybeari of the faunas of the lower Lias in Europe, which I
propose to name V. crossmani* The second fossil, from Inyo county,
was considered by me in the work already quoted to be identical with
Amioceras humboldti, hut a reexamination of the same specimens made
in the summer of 1891 has satisfied me that this was an error. The pike
are more closely crowded, and there are slight constrictions at intervals
on the whorls of the nealogic (adolescent) stages. These disappear later,
giving way to slightly arcuate costa', which also differ from those of Amio-
ceras humboldti. I therefore propose for this peculiar form the name of
Amioceras woodhulli.i These facts all tend to the conclusion that the
lower Lias, having certain forms of undeniable European fades, occurs
in western and southwestern Nevada and perhaps in California east of
the crests of the Sierra.

It is impracticable at present to discuss the relations of these faunas
with those of the Lias on the western slopes of the Sierra Nevada further
than to say that they are undeniably older than those found at mount
Jura.

It is obvious, from all of these facts and others that might be men-
tioned, that the Jura occurs in widely separated patches, and that so far
;is now known mount Jura exhibits a larger number of fragments of the
series of the Jurassic system than any other known locality in the United
States, and that it was the best at which to make the first attempt to
study this system in detail.

♦ The type is number 4989, collection of the State Mining Bureau, San Francisco, California, eol-
iected by J. E. Crossman. There is one specimen with the. internal whorls and part of a living

chambering I condition, and two large fragments more compressed. It is ;i species having

n i line roiis whorls, as in tin' more generalized forms of the genus, straight numerous costse without
tubercles on Hi'' geniculse, but the latter are prominent cm the outer whorl anil look us if they
might have tubercles in later >t :i o->> -. The abdomen is channeled ami keeled.

fThe typo i- in the collection of the State Mining Bureau, San Francisco; number 7642, Inyo
i ounty, California, collected by D. S. Woodhull.

I.\ I I' i"i 801 . A m.. Vni . :; 1891 .

412 A. HYATT GEOLOGY OF THE TAYLORYILLE REGION.

Tabular View.
Geologic Names by DUler. Special Biologic Names. Similar Faunas in Europe.

JURA.

I rpper .Jura or Malm.

Hinchman tuff Stylina bed Corallian.

Bicknell sandstone Trigonia bed Callovian.

Middle Jura or Oolite.

,T n , ( Inoceramus bed )

Mormon sandstone 107 11 t r ■ a r-

( hpii;> rum-its bed - Interior Oolite.

Thompson limestone. - . Opts bed )

Lower Jura or Lin*.

Hardgrave sandstone.

Upper Lias.

TRIAS.

Hosselkus limestone

Swearinger slates

Halobia bed. . . .
Rhabdoceras bed
Daonella bed (?)
Monotis bed ... .

Lower Karnic.

Upper Noric.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 413-444, pl. 13

STRATIGRAPHY AND SUCCESSION OF THE ROCKS OF THE
SIERRA NEVADA OF CALIFORNIA

JAMES E. MILLS

ROCHESTER

PUBLISHED BY THE SOCIETY

A.UG08T, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP. 413-444, PL. 13 AUGUST 8, 1892

STRATIGRAPHY AND SUCCESSION OF THE ROCKS OF THE
SIERRA NEVADA OF CALIFORNIA.

BY JAMES E. MILLS.

{Presented before the Society December 29, 1891.)
CONTENTS.

Page

Introduction 414

( reneral Character of the Sierra Rocks 414

Division into two unconformable < i roups 415

< Jeneral Stratigraphy 415

< reneral Features of the Sierra 415

Dual Character of the Range 415

Approximate ( !oincidence of successive Axes of Uplift 416

Position of < >utcrops relative to Axes of Uplift 417

Axes of greatest Uplifting 418

Relative vertical I >escent of eastern and western Slopes 418

Strike and Dip 418

Unconformity of the Mesozoic and pre-Mesozi »ic 418

Epoch of Tilting 419

Character and Extent of Uplifting 410

The District more particularly described 420

Pre-Mesozoic Rocks 421

Eruptive Granite 421

Sedimentary Slates and < iuartzites 421

Pre-Mesozoic Rocks outside of upper Feather River District 42.°>

Age of the pre-Mesozoic I locks 424

Mesozoic Rocks 425

Principal Divisions 425

Lower Mesozoic Subgroup 42i>

Slates. < rreenstones and Limestones 426

Possiliferous Limestones 428

Jurassic or later Age of the Fossils 428

Mesozoic < Jonglomerate containing older Locks 429

Unconformity on. Claremont 430

Upper Mesozoic Subgroup 430

Thinly laminated Slates and Serpentines 430

Sel'| icnt i lie 431

UpperSlates 432

Li i not ones 4:!:l

I, VI I I'.i i i Gkoi Soc \m . Vol.. ::. 1801. ' U3)

414 J. E. MILLS — LOCKS OF THE SIERRA NEVADA OF CALIFORNIA.

Page.

Mesozoic Rocks outside of upper Feather River District 4:;::

Distribution of the Rocks 4:!:!

Fossiliferous lower Mesozoic Limestones 433

Eastern principal Area 435

Ammonites colfaxii 436

Mesozoic Exposures south of the American 43(5

Mesozoic Exposures south of the Merced 4.'!7

The Mesozi tic Series 4.">s

Natural Divisions 438

F( issil 1 lorizons 439

Alteration Products ... . 44(1

The quartzitic Alteration 440

Pyritous ( lharacter of the Pocks 440

Fissures and mineral Veins 440

Gold 441

Fissures containing Chalcopyrite 442

Age of the mineral Veins 443

Introduction.

General Character of the Sierra Rocks. — The great muss of the Sierra
Nevada consists of crystalline rocks (granites) and highly metamor-
phosed, tilted and dislocated sedimentary and eruptive rocks. There
are less metamorphosed strata of later age (Cretaceous and Tertiary) on
the western Hank at and near the foot of the range, and Tertiary and
Quaternary lavas and sediments deposited by streams occur on the
slopes and even on crests and peaks, especially of the northern half of
the range. But the great mass of the range is made up of granites and
of sedimentary and eruptive rocks so highly metamorphosed as to he
quite generally designated as the metamorphic rocks of the Sierra.

J. D. Whitney showed in his report on the geology of California, and
added confirmation in his work on the auriferous gravels of the Sierra
Nevada, that a portion of these metamorphic rocks are of Mesozoic age,
and in the same works he states, with less positiveness, however, that a
part of them are of Carboniferous age* The Mesozoic age of the rocks
regarded by Whitney as Jurassic is farther confirmed by C. A. White
and G. F. Becker, though White assigns them to a position at the con-
lines of the Jurassic and Cretaceous periods,f and Becker places them
higher up in the Cretaceous;;!; hut the limits of the groups of these rocks

*()n identification of Mesozoic fossils by W. M. Gabb and F. I'>. Meek, and of Carboniferous
fossils found outside of the Sierra proper by J. B. Trask am! fragments of fossils found within the
Sierra by W. M. Gabb.

T Bull. U. S. Geol. Survey, no. 1."., 1885, p. 26.

; Bull. I'. S. Geol. Survey, no. L9, Ins;,, pp. 9-18; also Bull. Geol. Soc. Am., vol. 'J. 1890, pp. 201-208.

DEFINITION OP THE SIERRA NEVADA. 415

have not heretofore been defined, nor have the rocks within the groups
been described with the order of their succession.

Division into two 'unconformable Groups. — By detailed examination of
the rocks of one district within the range and comparison with those of
other parts of it, I have been enabled to distinguish two unconformable
groups definitely, and to determine the succession of rocks within the
later of the two and partially within the older one, and, so far as my
surveys have extended, to map the areas of exposure of each. The later
group includes the rocks determined by Whitney to he Mesozoic, and, as
will be shown hereafter, includes none other than Mesozoic. I shall call
this group, for the purposes of this paper, the Mesozoic group, excluding
from consideration the unaltered Cretaceous strata exposed along the
western foot of the range.

The older group lias thus far yielded no fossils within the Sierra proper,
and 1 will designate it simply as the pre-Mesozoic group.

( rENERAL STRATIGRAPHY.

General Features of the Sierra. — Before entering upon a detailed consid-
eration of the two groups and the succession of rocks within them, it will
he well to present some general features of the stratigraphy of the range,
for they throw much light upon the order of succession ; and among strata
so tilted, faulted and altered it is necessary to use all the means at hand
to determine which are the higher or lower in the series.

The Sierra Nevada, as now defined, extends about o7<> miles in a north-
westerly direction, with the general trend of the coast of this part of the
continent, from near latitude 34° 48' to near latitude 40° 12' north. At
its southerly end it curves westward around the southern end of the val-
ley of California, and coalesces with the Coast range. At its northern
end it might he difficult, on purely geographical grounds, to distinguish
it from the Cascade range'; hut geological considerations leave no doubt
thai the Sierra ends northward where its metamorphic rocks pass be-
neath the Lavas of the Lassen peak district ; for that mountain and the
lava field stretching out southward from it occupy an area where, as
late as the Chico (upper Cretaceous) epoch, the sea passed around the
northern end of the Sierra, and where, as late as Miocene time, there
was still a depression occupied by fresh water.* Other reasons, from
structural geology, for thus limiting the range northward will be given
hereafter.

Dual Character of the Range. — In its northern portion the Sierra is
double, consisting of eastern and western divisions. The eastern division

*Geologyof the Lassen Peak District, by J. S. Diller, in 8th Annual Report of the IT. 3
i 5 . pari i. 1889, pp. 30 ■ I 12

410 J. E. MILLS — ROCKS OF THE SIERRA NEVADA OF CALIFORNIA.

laps far southward by the southern end of the western, and is much the
Larger mountain mass of the two.* It culminates near its southerly end
in mount Whitney, at an elevation of between 14,000 and 15,000 feet f
above sea-level. Its crest falls northward and, as a continuous crest,
terminates on the southern side of the Middle fork of Feather river. This
division of the range continues, however, northwestward from that stream
in broken sections to the edge <A' the great lava field west of Big meadows.
Besides being separated by the depression of the Middle fork of Feather
river, it is farther divided crosswise by the canyon of the East branch of
the North fork and the canyon of the main North fork of the same river.
It is known next north of the Middle fork as drizzly ridge, then ;is
Hough mountain or mount Hough, and north < if the East branch of the
North fork as Green mountain. It loses its distinctness as a topographic
feature north of the East branch, and ends north of the main North fork
west of Big meadows, near Prattville, where the metamorphic rocks pass
under the Tertiary lavas. The ranges east of the main crest and of the
mountains just named are here considered as belonging to the Basin
ranges.

The western division is highest near its northern end, and is most dis-
tinct topographically between the Middle and North forks of Feather
river.']: It rises there to 6,990 feet above sea-level at Spanish peak. It
falls rapidly southward and, as a topographical member of the present
range, disappears, merging into the western slope of the eastern division.
Geologically, it can be traced to American river, if not farther southward,
by the outcropping of granite and other older rocks of the series. Still
farther southward the main western division is replaced by two or more
minor uplifted masses on the western slope of the eastern division.

The duality of the northern part of the range is a very important geo-
logical feature. Each of the two divisions has its own axes, or, more
accurately, its own areas of habitual greatest uplifting ; and before the
Mesozoic upheaval the two were separated, at least during the period of
subsidence that preceded the upheaval, by an arm of the sea.

Approximate Coincidence of successive Axes of Uplift. — The present relief
of the range, or at least of the northern half of the range, is due princi-

*Tliis duality was recognized and, in a general way. described by Amos Bowman in a paper on
the "Geology of the Sierra Nevada in its Relations t<> Vein Mining," published in the 7th Annual
Report on Mineral Resources west of the Rocky Mountains by the U. S. Commissioner of Mining
Statistics, 1875.

f " Hence we conclude that it is highly improbable that mount Whitney should be less than 14,650
feet high." J. D. Whitney, in Auriferous Gravels of the Sierra Nevada, 1879, p. 28.

J The western division of the range really lies along an extension southward of the axis of the
Cascade range, and in a strict geological sense belongs to that range rather than to the Sierra
proper; hut it is probably impracticable to change the nomenclature so far as to make it eon form
to geological requirements in this respect.

kkcikkknt orogenic movements. 417

pally to Tertiary and Quaternary uplifting* but the axes of greatest
uplifting of the present range coincide approximately with axes of up-
lifting of previous ranges within the same area. In other words, repeated
orographic movements have taken place along the same axes, and recur-
ring uplifts along these axes have followed recurring erosion. In tins
way a pre-Mesozoic range arose, carrying up both crystalline and meta-
morphosed sedimentary meks, and partially disappeared through erosion
and subsidence; then a Mesozoic range arose and its strata became up-
tilted, and it in turn was reduced by erosion and subsidence to very
small proportions (in its northern half at least, 'nearly or quite to hase-
level of erosion) and then in Tertiary and Quaternary time has arisen
the present range, which is now undergoing its erosion; but whether it
is now rising or subsiding is not determined.

Position of Outcrops relative to Axes of Uplift. — The oldest rocks appear
along the axes of greatest recurring or habitual uplifting, and as these
are on the whole approximately coincident with the axes of the present
range, the oldest rocks in a given section across the range outcrop quite
generally along and near the crests and peaks of the present range, where
they are not capped by Tertiary lavas and sediments, and on the whole
the rocks highest in the series appear farthest from the crests. As
already stated, the coincidence of axes is not complete, and the relative
intensity or shear of uplift along the axes has varied greatly, as shown.
for example, by the fact that the area, of exposure of older rocks extends
far southward of the crest of the western division of the present range.
The succession is, moreover, frequently interrupted by faulting. How-
ever, the obscurity from these causes can be cleared away by noting the
habitual or prevailing position ol areas of outcrop of either of the groups
of rocks relative to the axes or areas of greatest and least uplifting. The
two principal axes of uplift are by no means the only axes of orographic
movement ; neither are the main or minor axes straight, unbroken lines.
Each main uplift is made up of a series of uplifts, and the mountain
masses are of very irregular shapes. They have, however, one prevailing
characteristic, namely, thai their Longer axes have the trend of the por-
tion of the range in which they occur.

The Tertiary and Quaternary uplifting to which the relative relief of
the presenl range is due has been principally, if not entirely, by faulting.
The history of the range includes also regional orographic movements,
both of elevation and subsidence, the character of which has not been
determined.

•This i- abundantly proven hy dislocation and uplifting of Tertiarj and Quaternary deposits
md by the obstructions to drainage which caused them ; bill I must I I >inent of

I fa i" u I'm in p ipor.

418 J. K.MILLS ROCKS OF THE SIERRA NEVADA OF CALIFORNIA.

Axes of greatest Uplifting. — A prevailing geographic characteristic of
the range is that the crest of each of its two great divisions and of its
individual mountains is near the eastern edge of the mass; in other
words, the easterly slope is much steeper than the westerly one. The
easterly slope may be called a fault-plane, though it is not by any means
a simple plane, hut a broken, jagged and irregular composite plane. The
western slopes also rise in part, if not wholly, by faults : but they are. as
a rule, of less shear, and form less prominent escarpments than those of
the easterly slopes. This is not, however, a universal rule. The westerly
slope of Grizzly ridge, for instance, rises from its foot by a fault, which I
have called the Cromberg fault, which can be traced and measured by
the dislocation of Tertiary deposits for over seven miles, and near the
hamlet of Cromberg, on the Middle fork of Feather river (in sections 12
and 13, T. -i:\ N., R. 11 E., M. I). M.), the uplift is more than 1,100 feel
vertically in 3,375 feet horizontally; bow much more than 1,100 feet I
cannot say, as the floor on which the Tertiary deposits rest at the down-
thrown (southwestern) side of the fault is not exposed.

Relativt vertical Descent of eastern and western Slopes. — The descent of the
eastern slope of the range as a whole is much less in vertical extent than
that of the western slope; for the interior basin, at the foot of the steep
easterly fare, is much higher than the valley of California, at the foot of
the westerly slope. The elevation above sea-level of Owens lake, at the
foot of the easterly face, nearly east of the summit of mount Whitney
and 12 miles distant from it. is 3, (lis feet,* while Visalia, in the valley
about 54 miles west of the summit of mount Whitney, is but 34S feet
above sea-level.f Lake Tahoe is. according to Wheeler, 6,202 feet above
sea-level, while the summit of Twin peak, about four miles away, is 8,82 1
feet, and the valley 54 miles west of Twin peak is 163 feet above sea-
level.

Strike and Dip. — The metamorphic sedimentary rocks of the range are
tilted to high angles with the horizon. The prevailing strikes arc parallel
to the general trend of the range and of the coast : the prevailing dips
are between 40° and vertical, and the Larger part of them between 60°
and vertical. The direction of dip over much the larger part of the area
is easterly; but in the northerly part of the eastern division of the range,
namely, on Grizzly ridge, Hough mountain, and northward to the edge
of the lava held, the prevailing direction is westerly, and north of the
North fork of the Feather this direction of dip extends further westward.
Unconformity of the Mesozoic and pre-Mesozoic. — The strike and dip are
but slightly affected by the Tertiary and Quaternary uplifting, and I

*Capt. Geo. M. Wheeler, U. S. Geographical Surveys West of the 100th Meridian,
f U. s. Signal ( ifflce Reports.

PREVALENCE OK FAULTING. 419

have not been able to discover any unconformity of dip and strike be-
tween the strata of the pre-Mesozoic and Mesozoic groups : but the strata
of the two groups are unconformable by erosion. Those of the older
group were raised above sea-level and eroded, and then subsided to re-
ceive Mesozoic sediments. Moreover, they, or at least some of them,
were metamorphosed before the erosion, for pebbles and bowlders of pre-
Mesozoic quartzites as well as granites occur in Mesozoic conglomerates,
as will be hereafter shown. It is probable that the pre-Mesozoic uplift-
ing was, like the Tertiary and Quaternary uplifting, principally by fault-
ing, and therefore of little effect upon the prevailing dip and strike.

Epoch of Tilting. — The upper Cretaceous (Chico) and Tertiary strata at
the western foot of the range dip westward at low angles. It follows,
therefore, thai the greater part of the tilting of the metamorphic rocks
took place before the later Cretaceous strata were deposited and after the
Mesozoic metamorphic rocks were deposited. According to Whitney's
determination, the Mesozoic tilting was done at the end of the Jurassic ;
according to Becker's apparently tentative and still incomplete deter-
mination, it was later or " post-Gault."*

Character and Extent of Uplifting. — A part, at least, of the pre-Tertiary
uplifting was by fault, for on the easterly face of Claremont (see accom-
panying map, plate 13) pre-Mesozoic rocks are brought into contact with
the highest subgroup of Mesozoic strata. The displacement is in part
Tertiary and Quaternary- but the extent of this part can he measured
by the dislocation of Tertiary sediments and lavas. At one point at the
northern end of Claremont the vertical relative displacement of the Ter-
tiary materials is hut 1,300 feet, while the pre-Mesozoic slates there are
brought into contact with the thinly laminated shales of the upper part
of the upper .Mesozoic subgroup. The greatest relative vertical displace-
ment of Tertiary deposits at Spanish peak and Claremont is but about
."..:'>oi) to 3,400 feet, while the shear of the fault is several times ;is great.
How much of the pre-Tertiary uplifting is due to pre-Mesozoic and how
much to Mesozoic movement I have found no means of testing.

How the .Mesozoic uplifting and tilting was effected is not clear. Willi
the prevailing easterly dips, later rocks are often carried beneath older
ones; in other words, the strata have been overturned. The most ready
inference is that the strata were thrown into anticlinal and synclinal
folds by approximately horizontal thrusting, that these folds were over-
turned, and that during or after the folding the mass was faulted. But
the slopes of the range are steep, and over a large proportion of the area
tlic rocks are bare, and deep canyons afford numerous and extended ver-
tical sections ; yet neither arches nor inverted arches appear, and I know

ill. Geol. Soc On vol. -'. 1890, pp. 201

420 J. E. MILLS ROCKS OF THE SIERRA NEVADA OF CALIFORNIA.

of no reason for assuming that there ever were such in the region. The
conditions point rather to tilting of irregular blocks formed by approxi-
mately vertical or steeply sloping faults, and included within and sepa-
rated from the surrounding mass by fault planes. Such blocks have
been formed by Tertiary and Quaternary uplifting; indeed, the uplifting
has been by blocks, and each mountain is a block. Moreover, as a rule
the block is raised higher near one of the two longer edges (more com-
monly the eastern edge) than the other — that is, the block is somewhat
tilted. If the pre-Tertiary faulting was principally Mesozoic, and the
tilting of the blocks was carried farther than the Tertiary and Quater-
nary tilting until commensurate with the Mesozoic faulting, the presenl
structural conditions would result — that is. the strata would he thrown
on edge and those of any given block would he without connection by
arches or inverted arches with corresponding strata of adjoining blocks.

The District more particularly described.

The district in which my studies and surveys have been most detailed
lies between the eastern and western crests and between the North and
Middle forks of Feather river, and as my most definite illustrations are
from tins district I shall describe it briefly.

The general topography and geology of the district are outlined on the
accompanying sketch map (plate 13).* Grizzly ridge, Hough mountain
and Green mountain form the eastern division of the range. Grizzly
ridge and Hough mountain rise on the northeastern side by steep escarp-
ment— a broken and jagged fault-plane — and on the southwest partlyby
steep escarpment and partly by slope, which however is steep. The
slopesand escarpments meet at the top in a sharp crest. At the westerly
side of the district rises Spanish peak mountain, which presents a very
steep escarpment eastward ; hut it- crest is the eastern edge of a plateau,
modified by erosion, some 13 to 14 miles wide. From the westerly edge
of this plateau the surface drops rapidly to the Great valley-of California.

Between the two divisions of the range north of the Middle fork of
Feather river rises an intermediate mountain called Claremont. There
are also other ridges and mountains formed by uplift with axes of various
directions — one running nearly eastward from Spanish peak mountain
along the southern side of the East branch of the North fork of the
Feather, and one between Spanish creek and the Middle fork, formed by
a southwesterly uplift from Claremont, and a southeasterly one from
Spanish peak. Detailed surveys have proved that the topography, which
appeared a1 firsl sight to he the result of erosion and a simple system of

Scale reduced from 1 inch I miles to 1 inch = C miles, or 1:380.060, in reproducing.

TERTIARY AND QUATERNARY DEFORMATION. I"21

uplifts, is in fact principally the result of a very complicated system of
orographic movements. These are clearly shown by dislocations of Ter-
tiary and Quaternary deposits which I have surveyed and mapped, but
to describe them is not practicable within the limits of this preliminary
paper. The main features for the present purpose are the eastern and
western divisions of the range, the intermediate mountain Claremont,
and the depression partly occupied by the American valley on the north-
eastern side of this mountain and Spanish ranch and Meadow valley on
the southwestern side of it, which depression is drained by Spanish creek
and its branches. Some of the principal elevations above sea-level are:
Outlet of American valley. 3,353 feet : outlet of Spanish ranch, 3,618 feet :
highest point on Grizzly ridge (barometrical), 7,952 feci ; Spanish peak
(barometrical), 6,990 feet; Claremont. 6,962 feet,

Pre-Mesozok: Rocks.

Eruptive Granite. — The principal exposures of the pre-Mesozoic rocks
in the Sierra are the two areas of greatest uplifting already described.
The eastern one extends from the southern end of the range to the
northern flank of mount Haskell, between the North Yuba and the
Middle Feather, where the pre-Mesozoic rocks pass beneath the Mesozoic.
The western area of pre-Mesozoic rocks extends from the northern end of
the range to the Great valley between Yuba and American rivers. Both
areas include isolated and peninsular tracts of Mesozoic rocks.

The granites form by far the greater part of the pre-Mesozoic rocks;
indeed, they make up the core and the great mass of the range and of
each of the two divisions of the range. I have not seen granite over-
Lying or penetrating sedimentary strata in the Sierra proper, but on the
easterly slope of one of the nearer basin ranges, a little south of Beck-
worth pa.-s i which is at the In 'ad of the Middle fork of the Feather), there
are dike-; of granite penetrating gneiss. I must add that my observations
of the granites have been, with few exceptions, limited to the northern
half of the range.

Sedimentary Slates "nil Quartzites. — While the core and mass of Spanish
peak mountain are of granite,* and the upper part of its eastern lace is
also of granite, lower down on this face, next to the granites, a series of
slates ami quartzites outcrop. The quartzites are evidently the slates,
altered by silicificatiori, for they retain the slaty structure, sometimes

♦ Professor LWendell who kindly exumined microscopically a specimen < ' m it <■

fur , wrote of it, October 22, 1888: "The Spanish p . ortho dase, phigio-

. ! i . . hornblende and biotiti litil constituents; this makes it :i hornblende-grunitit<

nbusch), li i- ili'- in.-- 1 widely spread granitic rock in ling t" m

experience." 1 1 cerl duly is the prevailing granite of the northern half of th • range.

I. VII I- B Six . \<i.. \ in.. '■. 1891,

422 J. E. MILLS ROCKS OF THE SIERRA NEVADA OF CALIFORNIA.

laminated, but more often in distinct layers half an inch to an inch and
more in thickness. The alteration occurs in all stages from that of some-
what siliceous slate to slaty quartzite and complete quartzite. The slates
and quartzite arc frequently contorted ; the contortion being local and
not caused by any general movement of the mass or by .pressure from
without, but by some locally acting force within the mass, probably
molecular force accompanying the chemical and mineralogical changes
of metamorphosis, causing alteration of volume and consequent displace-
ment.

These pre-Mesozoic slates and quartzites lie on the granite, and were
probably deposited upon it. as 1 have found no intrusions of the erup-
tive rock in the strata. They outcrop between the granite and Mesozoic
rocks, and Mesozoic strata come in contact both with them and with the
granite. It will he shown hereafter that fragments of both the granite
and quartzite are found in a conglomerate of the lower Mesozoic group,
and therefore that these rocks are older than those of that group and
unconformable with them.

The Claremont uplift has brought to the surface a series of pre-Meso-
zoic strata. There are no granites or other eruptives among them, and
they consist of highly metamorphosed slates. They retain more or less
of slaty structure, though rarely cleavable into lamina' or sheets of consid-
erable size, and they break with irregular, often more or les^ conchoidal,
surfaces and into more or less prismoidal fragments. They are curled
and contorted in much the same way as the slates and quartzites before
described, but much more generally than they. There is a very general
deposition or segregation of silica in the mass, evidently chemical. The
silica is in part disseminated through the slate, but much of it is lodged
in films on surfaces of cleavage or lamination, or in irregular hunches
and lenticular bodies or veins, sometimes crossing, sometimes lying par-
allel with the surfaces of lamination. There are micaceous surfaces, and
the mica and also an arrangement of the siliceous grains in the slaty
lamina' sometimes give a gneissoid form to the rock: hut there is not
enough of mica or micaceous felting to form a true gneiss. The rock is
sometimes chloritic, and some of the chloritic ledges have a massive form
that suggests eruptive origin.

It will he shown hereafter that limestones and slates of the oldest
Mesozoic subgroup of the district rest unconformably on these rocks.
They are therefore older than the oldest Mesozoic rocks of the dis-
trict. They are nowhere within this district exposed in contact with the
granites or quartzites of Spanish peak mountain, and there are not any
means here of determining directly the relative age of these and the
Spanish peak pre-Mesozoic rock-: hut farther northwestward, near the

INTERBEDDED QUARTZITES AND GRANITES. 423

northern end of the range, there is a nearly continuous exposure of the
contact of granite and sedimentary pre-Mesozoic strata for at least seven
miles from the West branch of Feather river, near the middle of T. 24
X.. 15. 4 E., M. D. M., northeastward along the divide at the headwaters
of Kimshew creek. The sedimentary rocks approximate in character
the pre-Mesozoic rocks of * llaremoht ; they are imperfectly gneissoid and
chloritic in part. Their strike is nearly at right angles to the prevailing
strikes of the Sierra, namely, northeasterly, parallel to the contact just
mentioned: and they dip at comparatively low angles northwestward
away from the granite. They pass by the northern end of the western
area of granite exposure here at the northern end of the western division
of the range, as the Mesozoic rocks pass by the granite of the crest of the
eastern division between the Middle fork of the Feather and the North
fork of the Yuba. Across the area of outcrop of these strata on the
northwestern side of it. about 41 miles from the contact with the granite,
at the Chaparral house on the Oroville and Prattville stage road, in sec-
tion 10, T. 24 N., R. 4 E., are quartzites like those on the easterly face of
Spanish peak mountain, with the ordinary northwesterly strike and a
nearly vertical dip. The metamorphosed, imperfectly gneissoid and
chloritic strata outcrop here between the granites and quartzites, and are
probably lower than the latter. They may he contemporaneous with or
older than the granite, although 1 have seen no intrusions of the eruptive
rock in these strata.

There are quartzites in the range contemporaneous with the granite
and imbedded with it, Such occur at and near the western edge of the
granite of the eastern division of the range, where the South Yuba Hows
oil' it. between live and six miles east of the village of Washington ; also
in granites outside of the Sierra proper, north of Sierra valley, at head-
waters of the Middle fork of the Feather. In both cases the quartzite is
probably a product of alteration of the granite itself.

Pre-Mesozoic Rocks outside of i'i>i><r Feather River District. — The pre-
Mesozoic rocks of this district are not typical of the whole group in the
Sierra, inasmuch as they do not include limestones which occur in great
masses among the pre-Mesozoic rocks of the western Bank of the range
from the Mokelumne to near the Tuolumne river. These limestones
occur in a group consisting principally of micaceous schists and quartzites,
lying nexl to granite and in places surrounding isolated areas of tins
granite. Whitney describes the group in the " Geology of California "
and also in his ''Auriferous Gravels of the Sierra Nevada." On the
Mokelumne, at the mouth of the North fork. I found an exposure of this
limestone 100 feel thick in a series of mica slates which, becoming
gneissoid, join the granite aboul two miles easl of the lime-tone. Pre-

424 J. E. MILLS — ROCKS OF THE SIERE.A NEVADA OF CALIFORNIA.

Mesozoic rocks continue west of the limestone on the Mokelumne about
eight miles. From this exposure of limestone on the Mokelumne to the
most southerly one described by Whitney is about 40 miles. These
gneisses, mica-slates and limestones underlie unconformably strata known
to be Mesozoic, but no fossils have been found in them and their age is
not definitely determined.

About midway between the Calaveras and Stanislaus rivers in the
Great valley, about three miles west of its eastern edge, is a small area of
granite. It adjoins Mesozoic rocks on the east and passes westward
under Tertiary deposits. It suggests an extension of pre-Tertiary uplift-
ing of the western division of the range far south of the Tertiary and
Quaternary uplifting of that part of the range. There is an area of pre-
Mesozoic gneisses and other rocks between the Mesozoic outcrops and the
Tertiary deposits of the valley on the Stanislaus ami a much larger one
south of the Merced, about Hornitas. The eastern area of granite conies
forward to meet the Tertiary of the valley near where the San Joaquin
cumes ont of the mountains/'- and only isolated areas of sedimentary
rocks are found on the western flank of the range farther southward.

Age of the Pre-Mesozoic Rocks. — -I have treated the pre-Mesozoic rocks
as of one group. It is not proven that they are all conformable or all of
one period. It is entirely possible that a part of them are Arehean and
a part Paleozoic, and that the latter part may include rocks of different
Paleozoic periods. Indeed, there remains a remote possibility that some
of them may he early Mesozoic. older than the oldest group that is proved
to he Mesozoic; but they are much more metamorphosed than these, are
unconformable with them, and after having been deposited were certainly
metamorphosed and uplifted, and the region had begun to subside again
before the lowest known Mesozoic strata were deposited. It is not there-
fore within reasonable probability that any of these rocks are later than
Paleozoic.

Besides being altered and tilted and faulted, the sedimentary rocks of
this group are very widely overlain by Mesozoic rocks, and their outcrops
are consequently disconnected; and fully to determine their order of
succession will require examination and comparison of a large part of
the areas of their exposure in the Sierra. The Mesozoic rocks, on the
other hand, are not overlain except by comparatively thin Tertiary and
Quaternary deposits, and therefore their sequence and natural division
into subgroups are more readily determinable in spite of faulting, tilting,
overturning and metamorphism. The district represented on the accom-
panying sketch map (plate 13) is a typical one for these rocks.

* According t<> ma]' by Win. P. Blake in his "Geological Reconnoissance in < lalifornia," 1853.

FOSSILIEEUOUS LIMESTONES OF THE SIERRA. 425

MESOZOIC Hocks.
PRINCIPAL HI Vis joys.

The Mesozoic group includes both sedimentary and eruptive rocks.
The sedimentary rocks consist principally of slates often altered to
quartzites, with, however, some limestones. The eruptive rocks may
naturally, though rather roughly, he distinguished as medium basic
lavas altered to diabase or greenstone, and very basic lavas more or less
completely altered to serpentines. Both kinds are still further frequently
altered to quartzites.

The whole group naturally tails into two subgroups, a lower and an
upper one. The lower subgroup is characterized by a large proportion
of the eruptive greenstones or diabases, while the upper one is character-
ized by deposits of serpentines, which in places attain enormous thick-
ness. The proportion of eruptive matter in both subgroups varies
exceedingly, and there is occasionally found a little serpentine in the
lower division and greenstone in the upper one; but as a whole the two
subgroups are characterized as stated.

Right at the confines of the two subgroups, but falling most naturally
into the lower one. is a series of limy slates and limestones. These
limestones are fossiliferous. The most numerous remains arc of crinoi-
dal stems, and, as hereafter shown, some of them belong to Pentacrinus
or an allied genus, and cannot be of earlier age than Jurassic. We
have, therefore, as a, lower limit for the lower subgroup of Mesozoic
rocks of the Sierra, the base of the Jurassic. They may. however.
belong higher in the series. At the top of the upper subgroup is a long
series of thinly laminated slate-. I have found no fossils in these slates
within the district of my more detailed examination represented on the
accompanying -ketch map lying between the North and Middle forks
of the Feather; but comparison with exposures of similar slates south
of Merced river(iu Mariposa county) and at intermediate points proves
conclusively thai they are of the same horizon as the A ucella-b earing
slates which Whitney, on the identification of F. B. Meek, determined to
he Jurassic,* and which White places on the confines of the Jurassic
and Cretaceousf and Becker assigns to a higher horizon in the Cre-
taceous ' post-< rault). 1

The fossils al these two horizons, one in each Mesozoic subgroup, show
that the whole group is above the base of the Jurassic, and this is con-
firmed by an ammonite which, as hereafter shown, occurs al still another

*Geologj ■'!' California, vol. i. (8G5, p. J.'''..

>i. Survey, no. I :.. I 85, p. 26.
I. Geol. Soc. Am.. \ ol. 2, 1890, pp. 201

42(j J. E. MILLS — ROCKS OF THE SIERRA NEVADA OE CALIFORNIA.

horizon in the lower subgroup. I have not found any certain uncon-
formity between these subgroups. The whole group seems to be one
long series of sediments and lavas deposited during a period of pre-
vailing though perhaps not uninterrupted subsidence of the region.

LOWER MESOZOIC SUBGROUP.

Slates, Greenstones and Limestones. — The greenstones or diabases of this
subgroup are of eruptive materials, hut these materials have quite com-
monly been transported to their present position and deposited there by
water. Stratification is not infrequently visible, and the transition from
massive greenstone to slate is sometimes gradual. The greenstone is
very often and over wide areas conglomeratic, made up of bowlders and
pebbles in a cement or groundmass of the same material, all of altered
lava exeept at times a small proportion of fragments of quartz and other
rocks. The bowlders and pebbles and groundmass have undergone much
the same kind and degree of alteration, and the surfaces and outlines of
the bowlders and pebbles are more or less obscure, but still are readily
recognized on fresh fracture, and often more plainly on weathered sur-
faces. The bowlders and pebbles are well rounded. The mechanical
condition and admixture of these materials are very similar to those of
much of the Tertiary andesite, which has been transported by water and
deposited in the same district, often on the greenstones. Between the
South Yuba and the American, as well as between the Mokelumne and
Calaveras rivers and elsewhere, lavas of this subgroup are exposed in
dikes, where, to the naked eye, at least, they are not chloritic, hut of dark-
gray colors or black, sometimes porphyritic, and often very similar to
Tertiary andesite. Professor Whitney says of this rock: "It appears
from Mr. Wadsworth's (not yet completed) examination to be a diabase
tufa, a much metamorphosed volcanic deposit. * * * Mount Bullion,
Juniper ridge, Bear mountain (on the Merced) and Merced mountain are
made up of this rock."* I have ^ven the exposures on mount Bullion
and .Juniper ridge, and the rock there is chloritic and largely conglom-
eratic, like the greenstones of the district under more immediate consid-
eration here. On mount Bullion they are also largely altered to quartzite.

The greenstones and slates of the lower Mesozoic subgroup form the
crest of Hough mountain and of the greater part of Grizzly ridge, though
covered in part by Tertiary deposits. At the southeasterly vm\ of Grizzly
ridge the}' come in contact with pre-Mesozoic granite. The main eastern
crest of the range is of these rocks from its northwesterly end south of the
Middle fork of the Feather to the northwesterly Hank of mount Haskell.

♦ Auriferous Gravels oflhe Sierra Nevada, 1879, p, 44.

CONTACT OF THE TWO SUBGROUPS. • 427

Here and southward granite forms the crest where not covered with
Tertiary materials, and the contact of these rocks and granite, passing
down the westerly slope of this part of' the eastern division of the range,
crosses the North fork of the Yuba about 4' miles east of Sierra city.

On the other (southwesterly ) side of this northeastern belt of the lower
Mesozoic subgroup its rocks come in contact with those of the upper sub-
group. The contact crosses the East branch of the North fork of Feather
river, here known as Indian creek, a little northeast of ShooHy, near the
crossing of the line between townships 25 and 26 X.. K. (.) E., then passes
on to the westerly slope of Hough mountain and of Grizzly ridge, and
crosses the Middle fork of Feather river between Bells bar and Nelson
point.

In the upper part of this subgroup where it crosses the .Middle fork
of Feather river and thence a little east of southward to tin,' North fork
of the Yuba, one to two miles below Sierra city, are numerous outcrops
of limestone. For the most part they and the rocks accompanying them
are very much altered, ami I have seen no fossils in them. In sections
11 and 14. T. 21 X., R. 11 E., are several masses of iron ore which seems
to he a product of alteration of the limestone. Near the Yuba there is
some serpentine associated with the limestone. These limestones un-
doubtedly belong near the boundary of the two subgroups, at the same
horizon as the fossiliferous limestones to he hereafter described. Whether
the, outcrops of limestone recurring at intervals continue south of the
North Yuba 1 do not know.

There is limestone exposed with a little serpentine in Little Long Val-
ley creek in section 12, T.£3 N.. R. HE. It is highly metamorphosed, and
1 do not know to what part of the lower subgroup it belongs. There is
a little serpentine near the crest of Grizzly ridge not far from its north-
westerly end. lint nowhere in this large eastern area of exposures of
the lower subgroup of Mesozoic rocks does serpentine occur in consider-
able mass. Near the crest of Grizzly ridge and near the divide between
the waters of the Middle fork of the Feather and of the North fork of the
Yuba and at (he Sierra buttes both slates and greenstones of this sub-
group are very generally altered to quartzites.

( >n the easterly face of Spanish peak mountain there are isolated areas
of greenstones and slates of the Lower Mesozoic subgroup resting on the
pre-Mesozoic slates and quartzites.

The rlareinont uplift has broughl pre-Mesozoic rocks in, contact with
mernbera of both Mesozoic subgroups, as shown on the sketch map. and
far northwestward of the present Claremont mountain the same uplifl
has dislocated the rocks and brought those of the two subgroups into
contact "lit of the regular order of sequence; so thai the rock- of the

-128 J. E. MILLS — LOCKS OF THE SIERRA NEVADA OF CALIFORNIA.

lower subgroup which have the serpentines of the upper subgroup on
the southwest in the order of sequence, have slates of the same subgroup
on the northeast by fault.

Fossiliferov.8 Limestones. — In the last named area of exposure of the
upper part of the lower Mesozoic subgroup occur the fossiliferous lime-
stones. The outcrops are not continuous, but occur at intervals from a
point on the southwestern flank of Claremont, in the N. E. \ N. E. I sec-
tion 4, T. 23 N., R. 9 E.,to and across Spanish creek and across the East
branch of the North fork of Feather river and the main North fork of
the same river to the divide between Mosquito and Yellow creeks, in the
western part of T. 26 N., R. 7 E., not far from the edge of the lava field
at the northern end of the range. The whole distance from the south-
eastern end to the northwestern end of this line of exposures is about
193 miles. From the southeasternmost exposure on Claremont to the
divide between the East branch of the North fork of the Feather and the
main North fork, a distance of 1-4 , miles, I have made detailed examina-
tion and surveys of the area, including the outcrops of these limestones
and of the rocks on either side. Thus examined and located, this long
line of outcrops of fossiliferous limestones in the heart of the Sierra afford
an' available and definite horizon from which to measure and determine
the position of rocks upward and downward in the series.

Jurassic or later Age of th Fossils. — The fossil remains are fragmentary,
consisting principally of sections of crinoid stems, though fragments of
brachiopod and gasteropod shells occur. Some of the crinoidal stem-
joints are simple, round, and with round canal in the center; others,
however, are pentagonal and have pentapetalous figures formed bycren-
ated edges on the articulating facets. I sent some of these crinoidal
stem-joints to Dr. Charles Wachsmuth, whose extensive and intimate
knowledge of crinoids renders his identification of them most valuable.
In a letter concerning these fossils, dated at Burlington, Iowa, November
18,1891, he says:

«* * * j examined them carefully and have come to the conclusion that they
must be at least of a later age than Triassic, possibly Jurassic. The stem-joints are
pentangular, with straight sides or reentering angles, and the facets in all of them
have that peculiar petaloid structure which characterizes the pentacrinidse, and
which occurs in no crinoid preceding the Jurassic. Scattered Let ween these stem-
joints there are numerous smaller pieces with a central canal, which I take to be
joints of the cirri, and of which in specimen 4 some are still attached to the edge
of the joint. On that specimen I also find a few perforated arm ossicles with deep
fossse, showing a highly developed articulation of the arms, such as is rarely found
in Paleozoic crinoids. The root on specimen 1 oilers no special interest; the lines
of union between the joints are serrated, but that is found even in some of the
earliest crinoids. That the stem is round at the distal end does not prove thai it

WACHSMUTH ON CRIXOID REMAINS. 420

was round also in the proximal part, as the form of the stem changes greatly in its
downward course, and it seems to me the upper face of the root shows traces of that
petaloid structure to which I alluded. The other specimens show the same thing
as number 4, but less distinctly. The genus Pentacrinus, winch made its appear-
ance in the Jurassic, survived to our present day ; and as the structure of the stem
remained almost unchanged, it is difficult to refer your specimen to any definite
age, but I am quite certain they are not older than Jurassic." * * *

Mesozoic Conglomerate containing older line];*. — The fossiliferous lime-
stones alternating with slates and greenstones are atone point associated
with a conglomerate containing pebbles and bowlders of granite and
quartzite. The locality is on Rush creek, a little less than a mile in a
straight line from its confluence with the East branch of the North fork
of the Feather, in the northern part of section 8, T. 25 N., R. 8 E. The
conglomerate is in contact with the limestone, and its cement is limy-
The granite of the pebbles and bowlders is like that of Spanish peak
mountain, and the quartzite like the pre-Mesozoic quartzites of the easterly
and northeasterly faces of that mountain, and there is no other probable
source of these bowlders and pel titles than within this westerly area of
uplifting. It is plain, therefore, that the granite- had cooled and crys-
tallized, ami the slates had been deposited and had undergone quartzitic
alteration and been raised above sea-level and subjected to subaerial
erosion, before these conglomerates were deposited on the beach of the
arm of the Mesozoic sea. These rocks are therefore unconformable with
the pre-Mesozoic strata, although no unconformity of dip and strike is
apparent, I saw one granite pebble or bowlder of more than 500 cubic
inches in size in the conglomerate.

The conglomerate is on the easterly edge of the limestones and limy
slates, which are exposed for a. widtli there of 5,300 feet and a thickness
of about 4,600 feet. On the west of them and between them and the pre-
Mesozoic rocks is the broad belt of serpentine three miles wide. I found
no fragments of serpentine in the conglomerate. The serpentine, being
an eruptive rock, may have keen deposited on land or in water, hut the
slates ami limestones were certainly deposited in the sea. If these and
the serpentines had been deposited when the pebbles of this conglom-
i rale were borne to the beach, they must have come across a width of some
miles of water, unless the serpentines and slates had been uplifted. Of
tins there is no evidence ; and as it is not possible that this beach material
came across an arm of the sea (one pebble of granite containing more
than 500 cubic inches'), H follows that the conglomerate and the green-
stones to the east of it are older than the slates and limestones ami ser-
pentines to the west of it. It is true that the serpentines now come in
contact with the pre-Mesozoic rocks al the faulted easterly face of Spanish

I.I \ I : i i i < ■ i . i 9<>i Vm., Voi,. 3 18(11.

430 J. E. MILLS — ROCKS OF TLIE SIERRA NEVADA OF CALIFORNIA.

peak mountain, but higher up on the face isolated areas of greenstones
and slates occur and, as hereafter shown, the greenstones, slates and lime-
stones come next to the same area of pre-Mesozoic exposures oh the west
between it and the ( ! reat valley, and in by far the greater number of eases
throughout the Sierra the rocks of what I have called the lower Mesozoic
subgroup outcrop between the serpentines and slates of the upper sub-
group and the pre-Mesozoic rocks.

Unconformity on Claremont. — The fossiliferous limestones and accom-
panying slates lie unconformably on the pre-Mesozoic slates of Clare-
mont. The contact and unconformity are plain to the eye where the
road from Quincy to Oroville crosses the neck of the " Devil's elbow," on
the left bank of Spanish creek, at the mouth of Rock creek, in section 18,
T. 24 N., R. 9 E. The unconformity on Claremont is plainly by erosion,
as no corresponding difference in dip and strike is apparent. There are
greenstones and limestones and a little serpentine in isolated areas on
and next east of the pre-Mesozoic area of this faulted northwestern end
of the mountain mass.

UPPER MESOZOIC SUBGROUP.

Thinly laminated Slates and Serpentines. — The upper Mesozoic subgroup
is the highest in the series of metamor'phic rocks. Its exposures therefore
lie generally in positions midway between the axes of greatest uplifting
and between exposures of the lower subgroup on either side, the latter
adjoining the pre-Mesozoic rocks still farther toward the right and left
and nearer the axes of uplift. Tins prevailing order of succession on the
surface is, however, often interrupted locally by faults. In the district
here under more immediate consideration, the northeastern crest of the
range is, as already described, of the lower Mesozoic subgroup; the south-
western crest and the face of the escarpment immediately below it on
the east are of pre-Mesozoic rocks, with isolated areas of the lower Meso-
zoic greenstones and slates. Between the two mountains the greater part
of the space is occupied with serpentines and slates of the upper sub-
group. The slates occupy the eastern part and the serpentines the
western part, and the two are separated by the long, narrow belt of pro-
truding older Mesozoic and pre-Mesozoic rocks brought up by the Clare-
mont uplift already described. As this belt approaches the Middle fork
of the Feather it narrows and ends near the river, where the slates and
serpentines of the upper subgroup come together. The area of exposure
of the serpentines is from 1.6 to 3.5 miles wide, and that of the slates
from 6.5 to 7.5 miles wide.

There is a narrow strip of serpentine outcropping on the easterly side
of the exposure of slate, between it and the older Mesozoic greenstones

THE THINLY LAMINATED SLATKS. 431

and slates of Grizzly ridge, along Spring Garden creek on both sides of it
above the American valley ( see sketch map, plate 13) : but farther north-
westward the serpentines are entirely absent and the older rocks brought
into direct contaet with tin,' slates by faulting*

There is another narrow strip of serpentine on the souttnvestern side
of the slates at contact with the limestones and slates of the upper part
of the lower subgroup, on the left bank of the East branch of the North
fork of the feather. There are also small isolated patches of serpentine
on the faulted northern end of Claremont near limestone and slates of
the lower Mesozoic subgroup and on pre-Mesozoic rocks. As the Clare-
mont uplift dies out southeastward, hornblendic slates come in on the
northeastern side of the pre-Mesozoic exposure, which belong to the
serpentine series.

Where the succession is uninterrupted .and where least interrupted by
faults the serpentine joins the slates and limestones at the head of the
lower subgroup. This is the ease for "JO miles along the line of ex-
posures of fossil iferous limestones before described. The slates at the
head of the Mesozoic series, for reasons to be hereafter given, may be
designated as the thinly laminated slates. Where the Mesozoic series is
complete or nearly complete the serpentines and slates which accom-
pany them lie between the thinly laminated slates and the rocks of the
lower subgroups. It is plain, therefore, that in the ascending series the
serpentines and the slates which accompany and replace them come
before the thinly laminated slates, and that the latter are at the head of
the whole series of metamorphic rocks of the Sierra.

Serpentine. — Throughout the area between the North and Middle forks
of Feather river the lower part of the upper subgroup of Mesozoic
rocks is almost entirely of serpentine, although there are some schists
with it. and a part of these are glaucophanic. The schists may be
made up of lava transported and deposited by water wholly or in part.
South of the Middle fork the proportion of serpentine diminishes and
slates increase. These slates are much like those of the lower sub-
group and less thinly laminated than those at the head of the series.

The serpentine is for the most part plainly (to the naked eye) a
product of alteration of a basic lava. The massiveness, cleavage and
absence of la in i i i;i t ;o; i or distinct plane-; of st ra t i licat ion all go 1" prove
this. M. E. Wadsworth describes, under the heading " peridotites," five
specimens of this rock from Sierra and Plumas counties within the dis-
trict next south of the one here more particularly treated of. and infers

*Thi the western 1 gh is a line of recur-

ring orographic n its, as shown by dislocations of Tertiary ■ I CJ ternary deposits and

ury drain i

432 J. E. MILLS — ROCKS <>]' THE SIERRA NEVADA OF CALIFORNIA.

from the structure as seen under the microscope that the serpentine
has replaced olivine and enstatite.*

Mr. J. S. Diller kindly gave me the results of microscopic examination
of typical specimens which I took from the le/t bank of Spanish creek
above the mouth of Rock creek and below Spanish ranch. He wrote of
these January 25, 1887 :

"Specimens numbered 1 ami i' are undoubtedly peridotites. Number 2 contains

a great deal of olivine, but most <>t it lias been altered to serpentine. Originally
there was evidently a rhombic mineral, probably enstatite, associated with the
olivine, hut now it has all disappeared and serpentine with oxide of iron have
taken its place. In specimens 1 and 4 no trace of olivine could he found ; all has
been altered to serpentine and magnetite; but the peculiar reticulated structure of
the serpentine indicates clearly that it was derived from olivine. I have no doubt
that these serpentines are altered eruptive rocks, peridotites."

These rocks can be found in all stages of alteration, from that of a dark
gray or black trappean rock, sometimes porphyritic, massive, cleaving
into irregular prisms, to that of an oil-green serpentine with conchoidal
fracture and smoothed and rubbed or " sliekensided " surfaces. It is
sometimes fibrous. In a geological sense, the whole mass can most con-
veniently be designated as serpentine, hut in a detailed lithological de-
scription it would be grouped under different heads according to original
minor differences in the lava and to different degrees of alteration. A
small proportion of the serpentine shows schistose structure and is more
or less micaceous. Whether this is sedimentary lava or detritus of other
rocks has not been determined.

The serpentine is in places altered to quartzite. Such quartzite after
serpentine occurs at the outlet of Spanish ranch valley; also on Rock
creek about three-quarters of a mile above its mouth.

Upper Slates. — These slates, as already stated, are at the head of the
series of the metamorphic rocks of the Sierra. Wherever 1 have seen
them freshly exposed by recent erosion or by artificial excavation they
are of dark blue or bluish-black color and very commonly pyritous.
The first effect of weathering is to cover the surfaces with red and
yellow oxides of iron, frequently with efflorescences of alum; in later
stages of weathering the red and yellow staining is removed and a light
gray, nearly white, often powdery surface is left on the laminae of the
slate. When thoroughly weathered the slates show themselves very
thinly laminated and fragile. At the outcrop this thin lamination is a
distinguishing characteristic. They are very largely altered to quartzite,
and the alteration is of a characteristic kind in this district. The result-

* Lithological Studies: A Description ami Classification of the Rocks of the Cordilleras, 1884,

p. 158.

FEATURES OE THE QUARTZITES. 43.']

ing quartzites are of two kinds; in one the .siliceous rock retains the
slaty felting and in part the slaty lamination, and this quartzite may be
described as silicated slate ; in the other kind the felting and lamination
have disappeared and the siliceous mass is often partially or completely
oolitic. The one kind passes into the other by gradation, sometimes
within a few feet. There are no sandstones among the slates in this
district, and I conclude that the difference is due to different kinds or
degrees of alteration, and not to original differences in the sediment of
which the rock was composed. The quartzites frequently pass by farther
alteration into clear, white massive quartz. The quartzite is commonly
dark gray when freshly exposed, but weathers to some shade of yellow
or red from oxides of iron, and then to gray.

Limestones. — There are limestones in these slates, as shown on the
sketch map (plate 13). They replace quartzites in the line of strike and
are otherwise so associated with quartzites as to indicate that the latter
have replaced the limestones, but lithological examination is necessary
to determine definitely whether this is so.

MESOZOIC ROCKS OUTSIDE OF UPPER FEATHER RIVER DISTRICT.

Distribution of the Rocks. — The greater part of the Mesozoic exposures of
the range are included within two principal areas, an eastern and a
western one. The eastern and larger one begins at the northern end of
the range and there includes its eastern crest, and extends in width west-
ward to the western pre-Mesozoic area, as shown on the sketch map
(plate 13). Farther southward it has the eastern pre-Mesozoic area on
the east, and lies between it and the western pre-Mesozoic area, and con-
tinues so to the southern end of the latter. There it lies between the
eastern pre-Mesozoic exposures and the unaltered Tertiary deposits of
the valley for the greater part of the distance to its southern end. which
is about I5miles southeast of the Merced, where the pre-Mesozoic rocks
come forward to the Great valley. Three minor arm- of pre-Mesozoic
exposures already mentioned lie between it and the Tertiary of the
valley, one 1 iet ween the ( a 1 a vera s and Stanislaus, one on the Stanislaus,
ami one south of the Merced aboul Hornitas.

The western principal area of Mesozoic exposures lies along the western
font of the range, between the ^ estern area of the pre-Mesozoic exposures
and the unaltered upper Cretaceous and Tertiary rocks of the Greal
valley, and extends southward from the northern end of the range to
where the granite of the western granitic area comes forward to the valley
between the Yuba ami American rivers.

Fossiliferous lower Mesozoic Limestones. — I have not seen the laminated
slates of the head of the series in the we- tern area, though there may he

1:34 J.K.MILLS ROCKS OF THE SIERRA N'EVADA OF CALIFORNIA.

outcrops of then) there; but the serpentines of the upper subgroup and
all the members of the lower subgroup arc represented there, and among
them the fossiliferous limestones. These occur near the contact with
the unaltered upper Cretaceous (Chico) and Tertiary deposits, along the
West branch of Feather river, at intervals from Nelsons bar bridge at
the mouth of a creek coming in from the right, to near the mouth of
Cherokee run above the bridge on the road from Cherokee to Yankee
hill. Nelsons bar is in theN. E. I section 7, T. 21 N., R. 4 E., and the
mouth of Cherokee run in N. E. I section 21, of the same township,
according to a map of Butte county. These limestones are referred to
as near Pence's ranch by Whitney, and on identification of imperfect
specimens of fossils by Gabb, he called them Carboniferous.* They lie
on both sides of the river, which here flows in a southeasterly course.
They occur at different horizons in the section for about three-quarters
of a mile in width of outcrop (dips, northeasterly at very high angle, or
vertical).

At the northeasternmost outcrops, which are on the left bank of the
river at Nelsons bar. serpentines are associated with the limestones.
There are also serpentines further southwestward, hut at the south-
westernmost outcrops (all on the right of the river) the limestones are
associated in places with greenstones, and a little farther southwestward
the greenstones become massive and continuous and form the crest of a
high ridge, on the southerly end of which is the village of Cherokee.
These greenstones are largely conglomeratic. I found no fossils in the
limestones on the left side of the river, but those on the right side of the
river ail' commonly fossiliferous, the fossils consisting principally of
fragments of crinoid stems. In my limited search I found no pen-
tagonal sections of stems, but many that were round with round central
canal, and some with lines radiating outward from near the canal.

These limestones lie about 34 miles directly across the western divis-
ion of the range from the outcrops of limestone already described,
stretching for 20 miles from the northern end of the range to Claremont.
Here, as there, they lie in a series of slates, of nearly the same thickness
in each case, between greenstones on the one side and serpentines on the
other, with some greenstones associated with the lower limestones, and
serpentines near the upper ones. It is true, 1 found no pentagonal
crinoid stems in the limestone at the western foot of the range, but at
some of the exposures between Claremont and the northern end of the
range the sections of crinoid stems are also all round. I see no reason
to doubt that these limestones, with accompanying slates, greenstones
and serpentines, lying at the northern end of the range on the two sides

Geologj of < alifornia, vol. i, L865, p. 209 ; Auriferous Gravels of t lie Sierra Nevada, 1879, p. SS.

IDENTITY OF LIMESTONE BELTS. 435

of the western pre-Mesozoic area, so closely allied in litbological char-
acter, position, sequence and character of fossils, were deposited under
indentical conditions, and are of the same age — Mesozoic.

About a mile southwest of the line of limestone outcrops, along the
right side of the West branch of the Feather, in N. W. S section 19, T. 21
X., R. 4 E.. are two small exposures <A' limestone containing crinoidal frag-
ments. A short distance westward the metamorphic rocks pass beneath
Tertiary deposits, and consequently it is difficult to determine the exact
position of these limestones in the series. It is probable, however, that
a fault intervenes, and that these' are of the same horizon as those along
the right side of the West branch.

Eastern principal Ana. — In the eastern principal area of Mesozoic ex-
posures the broad belt of serpentine, though varying in width and pos-
sibly interrupted in places, extends from the northern end of the range
to and across the Middle fork of American river. It therefore furnishes
convenient means of connecting the exposures of this area generally as
far south as to the last-named stream with those of the district already
described. 1 have followed it from this district southward to midway
between the Middle fork of the Feather and the North Yuba. It is
credibly reported as crossing the North Yuba between Downieville and
Goodyears bar, and this is confirmed by Professor W. IT. Pettee* Its
eastern edge crosses the South Yuba at the village of Washington, the
North fork of the American near Damascus, and the Middle fork of that
river west of Michigan bluffs. Its western edge crosses Hie last-named
stream in N. E. 1 section 1, T. 13 N., R. 10 E. Here, at its western edge,
ia a Large outcrop of pyritous talc.

1 have not had opportunity to study the rocks next east of this ser-
pentine hell farther southward than midway between the Middle fork
of the American and the North Yuba. To that point the outcrops of
thinly laminated slate continue from the district already described on
the eastern side of the serpentine. From the South Yuba to the .Middle
fork of the American a broad area of the thinly laminated shales at the
head of the series adjoins the terpentine licit on the west. At one place
between the North and Middle forks of the American, where 1 have hail
opportunity to locate it roughly, the width is about •'! miles.

Wes1 of the area of exposure of thinly laminated -late- again comes

rpentine, with talcose rocks and slates, not in so widean area as on the
eastern side of the thinly laminated slates or so constant ; still, exposures
of serpentine with some talc are frequent, and they and the slates of the
same horizon I lower part of upper Mesozoic subgroup) are probably con-
stant from near Nevada city to the Middle fork of the American. How

♦ Whitney's Vuriferoun (iruvels of the Sierra Nevaihi, 1870, :

1:36 J. E. MILLS — ROCKS OF THE SIERRA NEVADA OF CALIFORNIA.

much farther they extend north and south of these limits T do not know.
The serpentines show themselves on the railroad between Nevada city
and Grass valley, and at the crossing of Greenhorn creek, and between
there and the crossing of the Rear. On the same railroad, about a mile
north of the Central Pacific railroad, is massive talc of the same horizon
and very similar in character to that on the eastern side of the thinly
laminated shales near the serpentines at the Middle fork of the American.
Serpentines also occur west of the thinly laminated shales between the
North and Middle forks of the American at a locality which is probably
in section 13, T. 13 N., R. 9 E.

West of these serpentines and slates are exposures of the rocks of the
lower Mesozoic subgroup, and they continue westward to the pre-Mesozoic
gneiss and granite. The Central Pacific railroad crosses them from the
contact with the gneiss about a mile southwest of Auburn to near Cape
Horn. They consist largely of eruptive rocks (diabase), which have not
here, as already stated, the prevailing chloritic character, but are of gray
and black colors, sometimes porphyritic, and often resembling, to the
naked eye. the Tertiary andesites. They often occur in dikes, traversing
both slates and eruptive masses. East of Colfax, between it and ('ape
Horn, limestones occur, as they also do under Cape Horn, near the river.
These limestones hold the same relative position at the head, of the lower
subgroup between the diabases or greenstones below and the serpentines
above as at the northern end of the range.

Ammonites colfaxii. — One mile west of Colfax Professor Whitney found
specimens of an ammonite which Gabb describes as Ammonites colfaxii,
and referred with certainty to Mesozoic time and with some hesitation to
the Liassic epoch. Whitney calls it a " secondary fossil."* It was found
in the slates and diabases which underlie the limestones at the head of
the lower Mesozoic subgroup. It is therefore from a somewhat lower
horizon than the fossils found in the limestones at the northern end of
the range, and this affords confirmation of the Mesozoic age of the lime-
stones near Pence's on the West branch of Feather river.

Mesozoic Exposures south of the American. — From the South fork of the
American to Sutter creek I have not had opportunity to examine the
rocks.

From Sutter creek to the Tuolumne the area of Mesozoic exposures
lying between the pre-Mesozoic rocks on the east and the Great valley on
the west is approximately 12 to 15 miles wide. Within the area are two
prominent axes of uplift, having the general trend of the main range, and
along these axe.-, between the Calaveras and Stanislaus rivers, are two of
the minor mountains above mentioned, the western one rising from the

:: Auriferous Gravels of the Sierra Nevada, 1819, pp. 37-41.

THE "mother lode." 437

edge of the Groat valley, culled Gopher hill, the eastern one Bear moun-
tain. The valley between the two is 3 to 4 miles wide. Along the axes
of uplift the exposures are principally if not wholly of the greenstones
and slates of the lower Mesozoic subgroup. Between the long narrow
belts of these exposures lie outcrops of the upper subgroup, and south of
the Calaveras, if not north of it, the serpentines and slates and the thin
slates of the upper subgroup occur again east of the easterly one of the
two axes of uplift, followed by the greenstones and slates of the lower
subgroup, which continue eastward to contact with pre-Mesozoic rocks.

Large masses of limestone occur in this normal position in the series
at the head of the lower subgroup in places. The exposures of such
masses are especially frequent between the Calaveras and Mokelumne
and between the greenstones and lower slates brought up along the east-
erly one of the two axes of uplift on the east and the serpentines and
their accompanying slates on the west. I found a fossil coral at one of
the exposures at a Limestone quarry on the road from Campo Seco to
Mokelumne hill, a little less than 31 miles from the former in a straight
line, in the X. E. I S. E. 1 S. \V. ! section 23, T. 5 X., R. 11 E.

A striking feature of this .Mesozoic area is the great gold-bearing quartz
lode called the " Mother lode." It occurs within the most easterly area
of exposure of the lower subgroup, the one lying next to contact with
the pre-Mesozoic rocks on the east. I have not had opportunity to de-
termine its exact position in the subgroup north of the Calaveras, but
between the Calaveras and Tuolumne it is. when present, at the head of
the lower or greenstone-bearing subgroup and at or near contact with
the serpentines and slated of the upper subgroup. At one place near
Carson Hill village it passes over the line between the two subgroups a
short distance and outcrops among serpentines and their accompanying
slates.

Where the Tuolumne Hows out to the valley at Lagrange there are
greenstones of the lower subgroup and slates which are probably of the
upper subgroup. Where Merced river comes out of the mountains at
Merced falls the metamorphic rocks in contact with the Tertiary de-
posits of the valley are the thinly laminated slates at (be bead of the

Mesozoic series. Farther southward, on the road from Merced falls to
I [ornitas, I -aw a small isolated patch of these slate- Lying on pre-Meso-
zoic rock-.

Mesozoic Exposures south of th< Merced. — East of the pre-Mesozoic area
about Hornitas already briefly mentioned, and extending southeastward
from the Merced about L5 miles to where the pre-Mesozoic gneisses and
granites come forward to the valley, are two mountain-, already noted ;
the western is called Juniper ridge, and the eastern mount Bullion. The

I.X I'.i o . i.i mi ~.„ , \Mi. \ ,,, :, ism.

438 J. E.MILLS— ROCKS OF THE SIERRA NEVADA OF CALIFORNIA.

mass of both mountains consists, as before said, of greenstones and slates
of the lower Mesozoic subgroup. The greenstones are largely conglom-
eratic and are largely altered to quartzite. In mount Bullion, at the
west of the principal mass of greenstones, is a series of slates with lime-
stones. Both slates and limestones are exposed on the Merced, and also
nine miles southeast of the river. The limestones are siliceous, and no
fossils have been found in them. Next west of these slates and lime-
stones outcrop serpentines on both sides of the Merced and at points for
10 miles southeast. Farther southeastward they are replaced by talcose
rocks, which probably belong to the same horizon as the serpentine, and
these continue southeastward to the contact with pre-Mesozoic gneiss.
The serpentines on the Merced are in part altered to quartzite, and tins
alteration is exhibited unmistakably and on a large scale on the right
side of the river. Thinly laminated slates follow next west of the ser-
pentines on the Merced, and they continue southeastward at least 11
miles. They form the floor of the narrow valley between the two moun-
tains ; at Bear Valley village the area of outcrop of these shales is about
a mile wide. Here in these shales were found the Amelia and other
fossils by which Professor Whitney established the Mesozoic age of this
part of the metamorphic rocks of the Sierra. He, on the identification
of Meek and Gabb, considered them Jurassic; while, as already stated,
White places them at the confines of .1 urassic and Cretaceous, and Becker
places them still later in the Cretaceous.

There is faulting at the western foot of mount Bullion, as shown by
excavations on the great quartz lode there. Professor W. P. Blake men-
tions a fault in the Princeton mine, which is on this lode 9 miles south-
east of the Merced, in a report on the mine which I have not now at
hand to refer to. It is plain from maps and reports of the mines, as well
as from interruptions of the exposures at the surface, that the lode occu-
pies a fissure at a fault plane. But the succession of the rocks, although
obscured in places by the faulting, is essentially the same as at the
northern end of the range.

THE MESOZOIC SERIES.

Natural Divisions. — The Mesozoic series is essential^ the same through-
out the two great areas of exposure, and is as follows in descending
order :

T^ , ( Thinlv laminated slates:

Upper subgroup < Q1 , J j <■

11 t I folates and serpentines.

r , ( Slates and limestones with some greenstones;

Lower subgroup < Q1 , , ,• ,

1 Mates and greenstones or diabase.

SUCCESSION OF MESOZOIC LAVAS. 439

The limestones of the series are not continuous and are frequently
absent, and they occur in places elsewhere than in the third member of
the series; hut they arc characteristically frequent and extensive in this
member. The serpentines are also not constant in the second member,
or the diabase or greenstone in the lowest member; but there is no very
large area of exposure of the former without serpentine or of the latter
without greenstone or diabase. Serpentine sometimes occurs in small
proportions in the lower subgroup, and south of Sutter creek the green-
stones are not entirely confined to the lower subgroup, hut occur in
small proportions among the serpentines and slates accompanying them
of the upper subgroup, and possibly among the thin slates at the head of
the series. There are also in the more southerly exposures of the thin
slates some sandstones, and at one place near Montezuma, between the
Stanislaus and Tuolumne rivers, I have seen among them a fine con-
glomerate. I have not found limestone among these thinly laminated
slates except in the district described-, between the East branch of the
North fork and the Middle fork of Feather river. The non-chloritic
character of the diabase in a part of the exposures shows a difference in
degree or kind of alteration, and there are other minor differences. Still,
there are enough distinguishing characteristics of the several subdivisions
of Mesozoic rocks common to each throughout the areas of exposure to
render it readily identified.

The division of the Mesozoic rocks into upper and lower subgroups
simply brings out to view the characteristic eruptive activity and depo-
sition at the different horizons. The principal eruptives in the pre-
Meso/.oic series are granites; in the lower Mesozoic, diabase or green-
stone, products of alteration of a medium basic lava: in the upper
Mesozoic, serpentine, ;i product of alteration of basic lavas. The succes-
sion of lavas in the Sierra in Mesozoic time is similar in one respect to
thai of Tertiary time, when the principal outflow of basalt followed the
principal outflow of less basic lavas.

I have not attempted to give the thickness of the Mesozoic series or
any of its members.;!.- it Is obscured by faulting: but data are accumu-
lating which will, I trust, make it practicable to eliminate the errors
from this source. The whole series is certainly several miles thick.

Fossil Horizons. — In three of the four natural divisions of the Mesozoic
series fossils haye be. n found, namely, in the thinly laminated shales at
the head of the series {Aucella, Belemnites, etc, on the Merced, Mariposa
county); in trie slates ami lime-tones with greenstones (crinoids with
pentagonal stems, etc. at the northern end of the range): and in the
lowest division, consisting of slates and diabase or greenstone i Ammonites
colfaxii, on the ( 'eiitral Pacific railroad i.

440 j. k. mills — locks ol the sierra nevada of california.

Alteration Products.

The quartzitic Alteration. — The details of metamorphism belong to
lithology, but the quartzitic alteration is so general and on so large a
scale in the Sierra that it becomes an essential and characteristic feature
of the geology of the range. As before shown, there is quartzite after
granite near the Sierra, if not within the range, and on a large scale after
slate-, both pre-Mesozoic and Mesozoic, and after greenstone and serpen-
tines, and less certainly perhaps but to all appearance, to the naked eye,
after limestone. In places the quartzite passes into pure white quartz.
Quartz is found in lenticular masses and veinlets isolated from any
fissure, in the quartzites and in the slates, and in fact in all the rocks,
and such deposits of quartz are especially numerous in the pre-Mesozoic
slates; and finally, quartz occupies much the greater part of the space
between the walls of fissures throughout the Sierra.

Pyritom Character of tin Rocks. — Another characteristic which is so
prevalent that it cannot he omitted from a geological account of the
range is the abundance of pyrite in the slates. From the outcrops alone
no adequate idea of the proportion of pyrites could he obtained, hut the
more recent erosion and the tunnels and other mining excavations show
a widespread distribution of pyrite throughout the slates. On account
of the presence of pyrite, the slates weather to yellow and red colors at
their outcrops : indeed, the color of the debris resting on the outcrops can
he taken as an indication of the age of tin/ surfac< — the debris on surfaces
formed by more recent erosion is of gray color, while at surfaces as old as
early Quaternary, or. more decidedly, as old as late Tertiary, the debris
is of red and yellow colors. Of the pyrite in the green-tones or diabases
I cannot speak with confidence; near fissures I have seen greenstone
very pyritous. From the results of microscopic examination before
quoted, it is probable that the iron in the serpentine is in the form of
oxides rather than sulphides. Mas<e< of chromic iron ore are found in
the serpentine.

Fissure* mid mineral Veins. — Quartz, which is so large a product of altera-
tion of the rocks of the Sierra, forms the great bulk of the material tilling
fissures, and pyrite, winch is so widely distributed in the slates though
in far less proportion than quartz, is much more abundant than any
other mineral except quartz among the contents of fissures. The fissures
are generally, perhaps always, at fault planes; they are effects of uplift-
ing forces, and the mass on one side of each fissure is usually, if not
always, uplifted farther than on the other. As already stated, the prevail-
ing direction of the axes of uplift i< approximately parallel to the strike
of the rocks, and consequently this is true of the prevailing direction of

FEATURES OF THE FISSURES. 4-11

the fissures. But they sometimes run in other courses. Between the

Middle fork of the American and the Yuba there is a scries of fissures
trending directly across the strike of the rocks. One of these, on Jami-
son creek at the Plumas Eureka mine, has yielded a large product of
gold. At the same mine there are a number of so-called "Hat veins"
near and connected with the fissure, which are cleavage crevices enlarged
and filled with quartz and pyrite containing gold.

Gold. — The occurrence ofgold is not only most important economically,
but is also a very important geological characteristic of the Sierra. The
gold is associated with quartz, various sulphides (pyrite, chalcopyrite,
galena, etc), and other minerals, hut the essential accompanying minerals
are quartz and pyrite. Gold mining in solid rock is called " quartz min-
ing," and the treatment ofgold ore consists principally in separating the
valuable metal from quartz and " sulphurets." It occurs with quartz and
pyrite both in fissure- and outside of fissures where the quartz is a pro-
duct of alteration of slates arid other rocks, and its occurrence seems to
he connected not only with the precipitation of quartz and pyrite in
fissures, but also with the presence of pyrite and the quartzitic alteration*
in the rocks of the range generally. The richest deposits of gold in the
solid rock, however, and all or nearly all that have been found rich
enough to he profitably worked on a large scale in the Sierra are in
fissures. The gold is very unequally distributed through the quartz of
the fissure; frequently only a pail of the thickness of the lode can be
worked, and profitable mining, where it exists at all, is always limited to
certain areas of the lode called ■•chutes " or "chimneys," and it would
in nearly all cases effect a large saving of cost to find and use every avail-
able means of determining as early as possible the trend of the axes and
outlines of these areas.

Gold-bearing fissures occur in both the pre-Mesozoic and Mesozoic
rocks, [n the granites gold quartz lodes have been found more or less
productive, as at Granite basin, between the North and Middle forks of
the Feather, also between the Sanislaus and Tuolumne south of Sonora
and elsewhere, but E believe nonesuch have been found far from contact
with other rocks, and the great area of granite exposures, which includes
much the larger part of the Sierra, has been barren ground for miners.
In the pre-Mesozoic sedimentary rocks rich deposit- have been found at
and near Sonora. between the Sanislaus and Tuolumne rivers. These
rocks are traversed by dikes of eruptive matter, which to the naked eve
appears like the Mesozoic diabase, and the dikes were probably formed
and filled iii Mesozoic times. The gold occur- mostly in and near th<
dikes, and therefore it probably should be classed with the gold deposits
of (he Lower Mesozoic subgroup. The pre-Mesozoic rocks of the district

442 J. E. MILLS — ROCKS OB' THE SIERRA NEVADA OF CALIFORNIA.

south of Merced river, about Hornitas, have also yielded considerable
quantities of gold.

Gold lias been found in all the members of the Mesozoic series except-
ing the serpentine; but much the most productive part of the series and
of all the rocks in the Sierra is what I have called the lower Mesozoic
subgroup, which includes the slates and greenstone- at the bottom of the
Mesozoic series and the slates and limestones and greenstones next above.
Nearly all of the deposits now most largely productive are in this part
of the Mesozoic series, excepting some in fissures and dikes, which,
though traversing older rocks, probably tor reasons already given belong
to the same Mesozoic age. As the lodes are generally if not always at
fault planes, they are < >ffcen at or near contact of this sul (group of Mesozoic
rocks with others of a widely different horizon, as at Nevada city, where
the contact is with granite.

Professor Whitney describes the before-mentioned great quartz vein,
called the "Mother lode,'' extending (not continuously) from the Mari-
posa estate to Amador county, as " Made up of irregularly parallel plates
of white compact quartz and crystalline dolomite or magnesite." * There
is a large vein in the greenstone-bearing group on the southeastern Hank
of Spanish peak mountain, which also consists largely of magnesian lime-
stone. The " Mother lode '" between the Calaveras and Tuolumne rivers
and also in Mariposa county south of the Merced, if not for its whole
length, is at the head of the lower Mesozoic subgroup. This is the hori-
zon of the fossiliferous limestones, and it is possible that the limestone of
the lode where it occurs belongs to this group of sedimentary deposits,
but it is also possible that it is a chemical deposit like the quartz.

The fact that the most profitably worked quartz deposits are in the
lower Mesozoic subgroup does not prove that the rocks of that subgroup
contain the most gold, but that they contain it in the form most avail-
able. In the other Mesozoic rocks (excepting the serpentine) and in the
pfe-Mesozoic sedimentary rocks there must be much gold in a more dif-
fused condition, for the gravels which are debris of these rocks are often
very rich. But I cannot here treat of the occurrence of gold further
than as it is characteristic of the geology of the series and its several
members.

Fissures containing Chalcopyrite. — In a long line of fissures near the
western foot of the range, chalcopyrite occurs with the quartz and pyrite
as an important constituent of the vein matter. The fissures are among
or near the greenstones of the lower part of the Mesozoic series. Such
deposits occur on the southern side of the Yuba, near Spencerville ; south
of Sutter creek, about 21 miles south of east of lone ; on the Mokelumne,

* Auriferous Gravels of the Sierra Nevada. 1879, ]>. 46.

DISTRIBUTION OP CHALCOPYRITE FISSURES. 443

near Campo Seco ; and between the Calaveras and Stanislaus in the val-
ley between Gopher hill and Bear mountain, and also near the western
foot of Gopher hill at Quail hill; and such deposits are reported as far
south as in Mariposa county, south of the Merced. At Copperopolis,
between Gopher hill and Bear mountain, they are worked on a consid-
erable scale for copper, and on a smaller scale at two or three other
points. Why this series of fissures along the western foot of the range
should differ from the fissures in the same rocks on the western slope of
the range generally in containing so much larger proportion of copper
pyrites with the quartz and iron pyrites is not clear, but the fact is of
geological significance.

Age of the mineral Veins.

The fissures are younger than the rocks they traverse, and consequently
those that traverse Mesozoic rocks were made or extended after these
rocks were deposited. The period of their deposition was one of prevail-
ing regional subsidence, as already stated, but it was a period of great
eruptive activity, as shown by the miles of thickness of diabases (or
greenstones) and serpentines. It is hardly probable that all this eruptive
activity took place without dislocation as well as Assuring. Moreover,
there are strong indications of faulting at that time, especially at or near
the boundary of the two Mesozoic subgroups, although no unconformity
among the Mesozoic rocks has been certainly established.

At the end of the deposition of the metamorphic Mesozoic rooks there
followed great uplifting, tilting and metamorphism, and certainly great
Assuring. A prominent part of the metamorphism was the quartzitic
alteration, which resulted in the production of quartz with pyrite and
gold, like that in the fissures. It is practically certain, therefore, that a
Large part of the Assuring and Idling of fissures in the Mesozoic rocks
occurred with the tilting and metamorphism at the time when the depo-
sition of these rocks ceased and they were raised above sea-level. A
Long period of subsidence; followed, with little if any dislocation, con-
tinuing through the later Cretaceous (Chico), the Eocene (Tejon i, and the
early Miocene. Then followed the Tertiary and Quaternary uplifting,
to which is due the relief of the present range. En these Tertiary and
Quaternary movements there has been great faulting along lines of old
fissures, and probably new lissnring; but we have gravels deposited by
stream- at the time of the early Miocene movements, and (hey are made
up Largely of quartzite and quartz with gold from Mesozoic as well as
pre-Mesozoic rocks, and much of the quartz and gold is from fissures.
It is therefore certain thai a Large part, at least, of the Assuring of Meso-
zoic roclcs and the Idling of fissures with quartz, pyrite and gold took

I I 1 J. ]■:. MILLS — ROCKS OP THE SIERRA NEVADA OE CALIFORNIA.

place at the time of the tilting and metamorphism of these rocks, and
thai possibly a part of it took place during their deposition.

It has been shown that the pre-Mesozoic rocks were raised above sea-
level and a part of them had undergone the quartzitic alteration before
the Mesozoic rocks were deposited. They were probably also more or
less fissured while being uplifted and altered, and the fissures may have
been at that time filled with quartz containing pyrite and gold. It is
entirely probable that a part of the gold of the Sierra is of pre-Mesozoie
age. and it is certain that a large part of it is of Mesozoic age.

A Large proportion of the gold product of the Sierra has been obtained
from Tertiary and Quaternary and Recent gravels, ami is of Tertiary.
Quaternary and Recent age. in the sense of having been detached, con-
centrated and deposited by streams of those times ; hut whether gold has
been deposited in veins within the Sierra proper since the Mesozoic uplift
has not been certainly proved or disproved. Professor Whitney saw a
vein of chalcedonic quartz traversing Tertiary gravels* and silica is not

infrequently found forming a cement of such gravels, and silicified w 1

is not uncommon in them. There is chalcedony, evidently deposited by
a now extinct hot spring, near the edge of a lava flow near Inde-
pendence, smith of the South fork of the Mokelumne. The fragments
of chalcedony, resting on partially kaolinized slate, have been moved
and washed for gold, hut whether the gold was from the chalcedony or
from the bed-rock on which it rested I could not learn in the short time
spent there.

It is certainly not improbable that some gold-bearing quartz was de-
posited by the solfataric action that accompanied and followed the great
Tertiary outflowing of lava : but the greater part of the gold-bearing
quartz was deposited in veins older than the Tertiary lavas, for debris of
such veins underlies the oldest of them.

* i teology of California, vol. i. I860, p.. 276; Auriferous Gravels of the Sierra Nevada, 1879, p. 330.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA

Vol. 3, pp. 445-452

THE GEOLOGY OF THE CRAZY MOUNTAINS, MONTANA

J. E. WOLFF

ROCHESTER

PUBLISHED BY THE SOCIETY

\i ..i st, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 445-452 August 8, 1892

THE QEOLOGY OF THE CRAZY MOUNTAINS, MONTANA.

BY J. E. WOLFF.

(Read before the Society December 29, 1891.)

CONTENTS.

Page.

Topography 445

< ieneral Structure , -446

Eruptive Rocks of the northern Area 449

Structural Aspects 440

Lithologic ( Iharacters 450

Features of tin.* Southern Area 4">o

Topography.

The Crazy mountains arc situated in centra] Montana, centering about
latitude 46°3 longitude 11"° 15'. Theyforra a high isolated range of the
Rocky mountains, lying about 30 miles cast of the easterly border of
the main mass of the mountains, and rise abruptly from the eastern table-
lands, attaining an extreme elevation of about 11,000 feet above sea-level.
The Yellowstone river flows around their southern end a few miles after
its exit from the mountains at the lower canyon, and the range is there-
fore in plain view from the Northern Pacific railroad for many miles
eastward from the town of Livingston.

The mountains trend a little west of north and arc about 40 miles long
and 15 or 20 wide. A Large branch of the Yellowstone, called Shields
river, which Hows southward along the western base, has cut a deep. Hat
transverse valley at its head nearly through to the eastward drainage;
and there divides the range into northern and southern halves. Of the
two i >oi-t ion- thus defined the southern reaches the greater elevation. It
has numerous sharp peaks, often of a jagged aiguill type, and the arrange-
ment of the drainage is distinctly radial, since the streams How westward,
southward and eastward from the central mass of high peaks. In moving
lip one of these streams toward t lie head wr lind the valley at first com-
paratively broad, bounded by high bluffs of nearly horizontal sandstones,

l.\l I'.i ii Gkoi 3oi \m . Vol., :. 1801. I 15)

44G J. E. WOLFF — GEOLOGY OF THE CRAZY MOUNTAINS.

which become cliffs as the spurs rise toward the peaks ; but on approach-
ing the central peaks the valley suddenly narrows for a mile or more and
the stream falls from a higher level 400 or 500 feet by cascades and falls,
and beyond this the valley again widens somewhat with a more gentle
slope to the head. This " fall-line" is found on all the radial streams,
and is plainly due to the local hardening of the Cretaceous rocks pro-
duced by the central stock of diorite, as described later.

The larger valleys have been occupied by glaciers, as shown by rock
scoring; and the markings are found 500 or even 1,000 feet above the
present stream levels. No lateral moraines were observed, but at the
leads of the streams there is considerable morainic material, and also
below the exits of the streams from the range, which here contains
large bowlders of the characteristic eruptive rocks occurring higher up.
The glaciation seems to have been entirely local. The broad benches,
stretching out for miles eastward, westward and southward, are covered
with water-worn pebbles from the range and may lie high above the
present stream beds, which have cut deep through them into the under-
lying sandstones. The change in elevation from these benches to the
spurs from the peaks is sudden, the difference of level between the base
and the summit of the range averaging perhaps 4,000 feet.

That part of the mountains north of the head of Shields river is lower
and the summits have the form of ridges or flat-topped dome-shaped
masses. Both here and in the southern half, outlying peaked summits
or buttes form a topographical feature.

( rENERAL STRUCTURE.

The general geology is comparatively simple.* The range lies in a
region of nearly horizontal Cretaceous rocks, extending indefinitely east-
ward in the great plains and westward to the edge of the frontal range,
where sharp uplifts expose the older rocks. These Cretaceous rocks are
found throughout the range and either horizontal or, if disturbed, with
generally low dips. They consist of yellow or brown sandstones and
occasional conglomerates, interstratified with yellow, drab, red. or black
shales and impure calcareous beds. The conglomerates in one place
contain large pebbles of an older (Carboniferous?) limestone ; the shales,
plant remains and small beds of impure coal. Xo attempt is here made
to assign them to a definite horizon of the Cretaceous, but the base at
least seems to belong with the Laramie, which a few miles westward lias
over 8,000 feet of strata. f

*J. E.Wolff: "Null's mi tli^ Petrography of tin- Crazy Mountains"; Neues Jahrb. Min., etc,
1885, i, p. 69, and 1890, i, p. 192.
f\V. II. Weed: Hull. Oc, |. Soe. Am., vol. •_'. 1890, |>. 360.

DOMED CRETACEOUS STRATA. 447

Iii the southern half the strata have a general inward dip at the outer
edge of the range, both in the spurs and adjacent benches; so that gentle
easterly dips arc found on the western side, northerly dips on the south,
and westerly dips on the east. In the interior this basin structure is in-
terrupted by dome-shaped uplifts, of which the most marked is that con-
nected with the central dioritic stock, from winch the stratified rocks dip
away with gently decreasing dips. This dome structure is sometimes
repeated on a smaller scale in the outlying buttes. An example exists
on the northeastern border between Little Elk and Big Elk creeks;* the
shales and sandstones dip about 30° in three directions from the center
of the dome, which has been eroded 300 feet lower than the sides, thus
forming a roughly circular basin a mile or two wide surrounded by lines
of cliffs. One small intrusive sheet can he seen in the upper strata, which
rapidly thins out. Still farther outward from the center of the dome the
strata have steep dips and contain numerous intrusive sheets or bedded
dikes. The eroded center seems to be due to the lack of protecting erup-
tive sheets at that point, making it easy for the erosive agents to cut deep
into the soft shales and sandstones.

In the northern half of the mountains the dome structure is developed
with less regularity and a tendency to longitudinal uplifts with steeper
dips and sharp crumples, producing long-crested ridges. An interesting
case is found on the northern side of the deep transverse valley at the
head of Shields river, consisting in the southern end of a long anticlinal
dome, the strata dipping southward, eastward and westward within the
space of a mile. They are here interleaved with numerous sheets of in-
trusive rocks, which curve around the sides of the dome with them and
even preserve this parallelism in sharp minor crinkles a few hundred
feet wide, by which the lines of outcrop make elbows. The present cresl
of the dome is formed by a master sheet or laccolite sixty feet thick,
which dips off from three sides; but erosion has cut through it on the
axis of the dome to the underlying soft shales, exposing to view a trans-
verse dike of the same rock, apparently a feeder of the laccolite. The
close conformity in greater and lesser crumplings between the intrusive
and sedimentary rocks makes it necessary to suppose tli.it the elevation
took place after the intrusion of the former, for it docs not seem possible
that an intrusive rock could force its way into all the details of a sharply
crumpled surface. This being the case, the eruptive rocks were exam-
ined with considerable interest at one of the sharp twists for signs of
crushing, and with the expectation of some trace of the dynamic meta-
morphism so common in folded intrusive sheets of the Archean and

I he topographic map i- nol reproduced here.

448 J. E. WOLFF; — GEOLOGY OF THE CRAZY MOUNTAINS.

Paleozoic ; but neither in the field nor in the laboratory was any structure
detected different from that of the rock under normal conditions.

The monoclinal buttes developed along either side of the range are very
striking, especially on the western side. They owe their present elevation
to the sheets of intrusive rock, which dip inward with the strata toward
the range at varying dip angles in the different localities. The most im-
portant of these is the group of three high outlying buttes north of the
head of Shields river (''Three Peaks" on the map), which are arranged
i n echelon on a mirth-south line, the crest lines of the two northerly ones
lying progressively east of the third or southerly one. The strata dip
about 30° eastward, and the three buttes have high cliffs facing westward
and gentle dip slopes eastward. The crests are formed by heavy sheets
or laccolites of intrusive rock from 250 to 100 feet thick, with minor
sheets at intervals below, interstratified with the shales and sandstones.
These master sheets bulge in the crest of the ridge, maintaining their
thickness for about a mile in the case of the northern and southern buttes,
and then rapidly thin out to a comparatively narrow bedded dike. Ac-
companying this diminution in size the crest of the ridge drops, and the
next ridge, formed by another bulging sheet at a different horizon, begins,
culminates, and dies out in the same way. This peculiar topography
seems therefore due to the intrusion of bulging sheets (laccolites) at
different levels in the horizontal strata, the major sheets not having
their centers in the same vertical line; the whole complex was then
tilted and eroded, the soft shales and thinner sheets being quickly taken
off, leaving the master sheets standing. In the Henry mountains Mr.
Gilbert has described the first conditions of intrusion without subse-
quent tilting.

Another peculiar type is found in the outlying butte near Martinsdale,
on the northwestern edge of the range. This has an oval form, is about
two miles long, and has an elevation of 600 or TOD feet above the plain
at its base. It is fringed by a line of high cliffs facing outward, through
which the interior drainage has cut an outlet. The top forms a basin
with gently sloping sides. The Cretaceous strata are found around the
base dipping gently inward, while the slopes and crest are formed by a
great capping eruptive sheet and at least one lower sheet, with thin inter-
vening beds of shale. The thickness of the great sheet was estimated at
365 feet and of the lower 150. In the center of the basin, on the summit,
erosion has cut nearly through the main sheet, leaving "tall pinnacles of
the eruptive rock standing in groups (sometimes 50 feet high), which
are due to the perfect vertical prismatic structure of the sheet. Loose
pieces of metamorphosed shale found on the surface at the highest point
seem to lie remnants of the original covering of the laccolite. The erup-

LACCOLITES, SHEETS AND DIKES. 449

tive sheets and basement shales have the form of a gently folded synclinal
basin which erosion has spared.

Eruptive Rocks of the northern Area.

Structural Aspects. — The eruptive rocks are of great interest and novelty.
They may be classified for purposes of description as dikes, sheets and
Laccolites, without any essential genetic difference. The writer has found
no evidence of surface Hows; all rocks appear intrusive and younger
than the enclosing strata.

The dikes are innumerable and occur in every part of the range, vary-
ing in widthand position. In the canyons cliffs of horizontal strata may
he seen a thousand feet and upward in height, which are intersected by
mazes of vertical and oblique dikes. Toward the interior of the range
these dikes increase in number. As an example, a dike was counted
every fifty feet horizontal on a long spur.

The sheets are closely connected with the dikes, which sometimes
spread out between the strata as sheets, or a sheet may cut obliquely
across the strata as a dike to another level. The sheets may be a hun-
(1 red feet thick and a mile in extent. It is noticeable that sheets i >ccur on
the eastern and western edges of the range where dikes are rarer, and it
seems to have been easier for the intrusion to force its way laterally.
The facts indicating that many of the sheets have; been folded with the
strata after intrusion have been alluded to.

The laccolites differ from the sheets only in their greater thickness and
bulging character. The greatest observed thickness of any one laccolite,
free from shale hands, was about -'150 feet, which would be increased to
500 if a thin shale parting were omitted. They have a well developed
pi-isniatic structure at right angles to the cooling surfaces, and hence the
upright columns lean to correspond with the amount of dip. The tilted
laccolites are. of course, best exposed, presenting cliffs on one side. The
intrusion generally follows the bedding for some distance, hut is liable
to cut obliquely across, and without reference to joint planes. In one
natural section a long splinter of shale 200 or 300 feet Long ami •"><> feet
thick is seen to have keen bent oil' by the splitting of the eruptive mass,
hut is still continuous with the shales at one end.

It is rare to see feeding dikes below the laccolites. They are some-
times cut. in common with the shales, by later vertical dikes of the same
or different rock which follow joints in the shales. A Limited contact
rrietamorphism is produced by the laccolites and thicker sheets at both
con i ad-, by which the shales are indurated and often changed to a green
color by caustic action. The changes in texture and even mineral com-
position produced by dillereiit conditions of cooling in the center and at

450 J. E. WOLFF; — GEOLOGY OF THE CRAZY MOUNTAINS.

the contacts of the laccolites are striking. The rock has a coarse, often
granitic, texture in the middle, but becomes dense and porphyritic within
a few feet of the contact. The thinner sheets and dikes have throughout
their mass the character of the contact varieties of the corresponding
larger masses.

Lithologic Characters. — Brief mention should be made here of the varie-
ties of eruptive rock thus occurring. The most prominent is a dark basic
rock found in all three forms (the laccolites reaching over 350 feet in a
single sheet), and having a coarse granitic texture in all but the dikes and
thinner sheets. This rock, originally found here by the writer in 1883*
was found to he composed of feldspar (in part triclinic), augite and
nepheline, with biotite, sodalite, magnetite, olivine, segirine, etc, acces-
sory; as an abyssal intrusive rock with the mineral combination nephe-
line, soda-lime feldspar, it filled a gap in the classification of Professor
Rosenbusch, and was called by him "theralite," as the first undoubted
representative of this family.

Associated with the theralite in parallel sheets or dikes are lighter
colored alkaline rocks with a much higher content of silica, which in the
thinner sheets correspond exactly in mineral composition and structure
to the effusive rock called acmite-trachyte (often phonolitic) and in the
heavy sheets resemble some eleolite-syenites (c. g., those from Arkansas).
Other sheets and dikes composed essentially of triclinic feldspar, augite,
hornblende, or biotite appear to belong to various groups ( diorite-porphy-
rite, camptonite, etc). The completed petrographical study of all these
varieties is expected to bring out interesting relations between composi-
tion, structure and geological occurrence.

Featukes of the Southern Area.

The geology of the central mass of peaks in the southern half remains
to he described. The radial drainage and " fall-line " features of the
topography are due to the presence of a central mass or stock of coarsely
crystalline diorite and granite, which has hardened and metamorphosed
the Cretaceous strata for the distance of nearly a mile outward. The
streams which head within the area of crystalline rock have to cut
through this contact /.one or ring of hard rock, beyond which they have
cut deeper into the normal soft strata and widened their valleys. The
diorite stock is irregularly oval in outline and is about 6 miles wide at
the greatest diameter. The rock is composed of triclinic feldspar and
hornblende, biotite. augite, hypersthene, often quartz and orthoclase,
with the usual accessory minerals, but the composition varies somewhat.

* Neues Jahrb., op. < - i t .

FEATURES OF TIIK SOUTHERN AREA. 451

The rock has a hypidiomorphous granular structure, is sometimes as
coarse as a coarse gabbro, but near the periphery becomes fine grained
and porphyritic and often lias a marked parallel structure due to motion
in the magma. A very basic coarse variety found near the center is
noticeable. The diorite is cut toward the center by masses of alight-
colored finer-graiiied granitite, which envelops fragments of the diorite.
It is surprising to see the similarity between this Tertiary diorite and
granite and the Paleozoic masses of similar rock found exposed on the
old eroded surfaces of the Atlantic states, as, for instance, on the northern
shore of Boston. In both cases the same black patches are seen in the
granite, referable here to enclosed dioritic fragments, and the same alter-
nations of basic and acid rock in streaks or " Schlieren " with parallel flow
structure. The diorite is found in place in the streams as low as the
8,000 feet contour and can be traced 2,000 feet higher, remaining quite
coarse.

The Cretaceous shales dip gently off from the dioritic mass as a dome,
but at the actual contact were found sometimes turned up on ed»-e and
interlaminated with the diorite. The}r have been profoundly altered by
the intrusive rock, preserving in general the stratification of the thicker
hands hut losing all shaly structure. The result is a dense flinty handed
rock, creamy white, green, or black in color, resembling thecontact rock
called "adinole." or coarser, filled with biotite, and more like "hornfels,"
a product of Paleozoic granite contacts. None of the zones of mineralogi-
cal change so characteristic of the latter were observed. This effect
extends out about 5,000 feet on all sides, gradually dying out, as certain
layers only are affected.

The diorite stock as well as the adjacent Cretaceous rocks are cut by
later vertical dikes of diorite-porphyrite and allied rocks: these dike-
swarm in the contact zone, accompanied by horizontal and oblique sheets
of similar rock. Mr. -I. P. Iddings, who visited this place in 1891, find-
that the vertical dikes, both in the stock and in all this part of the range,
have a general radial arrangement, with the diorite mass as an approxi-
mate center, repeating a fact observed by him in a smaller diorite stock
in the Yellowstone mountains. These Ion-- radial dikes extend outward
even into the benches at the southern base of the range.

This imperfed description can give hut a fainl idea of the beauty of
this -Teat massiv and its eontad ring. Its intrusion into nearly horizontal
late Cretaceous strata and the enormous subsequent erosion which re-
moved the overlying rocks enable us to see it now in nearly its original
condition with deep sections into its center, whereas in the older inn--. -
of granitic rock which we usually study the long-continued erosion and

452 J. E. WOLFF^ — GEOLOGY OF THE CRAZY MOUNTAINS.

movements of the crust have removed or altered many of the original
features*

The existence of this high range as an outlier is due to the facts that it
was the center of violent eruptive activity in post-Cretaceous time, and
that the presence of great masses of crystalline rock, combined with the
honeycombing of the soft strata by dikes, enabled the whole mass to
resist the erosion which levelled the adjoining country. The moderate
uplifting of some of the larger sheets with their enclosing- rocks also con-
tributed to this result. Warren Upham calls it a striking example of
the "eroded mountain range." t

It is hoped this sketch may present the claim of these mountains as a
grand geological model and one. for the Rocky mountains, easily acces-
sible. From Livingston or adjoining stations on the Northern Pacific
railroad it is an easy day's drive to the foot of the range; the canyons of
the larger streams on the east side are easily accessible by horseback and
at the entrance even by wagon, and it is possible to ride to the falls in
the contact zone. The outlying theralite buttes can all be visited by
wagon.

*A smaller l>ut apparently similar stock was observed in the northern half of the range, but not
studied in detail.
f A Classification of Mountain Ranges, etc. A.ppalachia, vol. vi, no. •'!. 1891, p, 204.

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
Vol. 3, pp. 453-541, pls. 14-16

PROCEEDINGS OF THE FOURTH ANNUAL MEETING, HELD
AT COLUMBUS, OHIO, DECEMBER 29, 30, AND 31, 1891

HERMAN LeROY FAIRCHILD, Secretary

(With Index. Also Contents, etc, of Vol. 3, pp. i-xii)

ROCHESTEB

PUBLISHED BY THE SOCIETY

November, L892

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA
VOL. 3, PP. 453-541, PLS. 14-16 NOVEMBER 9, 1892

PROCEEDINGS OF THE FOURTH ANNUAL MEETING, HELD
AT COLUMBUS, OHIO, DECEMBER 29, 30, AND 31, 1891.

Herman LeRov Fairchild, Secretary.

CONTENTS.

Page.

Session of Tuesday, December 29 454

Election of Officers and Fellows 454

Memorial of John Francis Williams 455

Fossil Plants from the Wichita or Permian Beds of Texas (discussion by
E. W. Claypole, Alpheus Hyatt and E. T. Bumble) ; by I. ( !. White . . . 459

Secondary Banding in Gneiss ; by William H. Hobbs 460

Paleozoic Formations of southeastern Minnesota (discussion by W .1 Mc-

Gee and C. W. Hall) ; by C. W. Hall and F. W. Sardeson I<; I

Evening Session of Tuesday, December 29 4(i">

Session of Wednesday, December 30 466

Report of the Council 466

Second Annual Report of the Committee on Photographs 47<i

Notes on the Geology of the Valley of the middle Rio Grande 'discussion

by W J McGee) ; by E. T. Bumble 483

Relationship of the glacial Bakes Warren, Algonquin, Iroquois and Hud-
son^ "hamplain (abstract) ; by Warren Upham 4s |

The Iroquois Shore north of the Adirondacks; by .1. W. Spencer 188

Channels over Divides not Evidence per se of glacial Lakes: by J. W.

Spencer 4'.l|

Votes on the Geology of the Yukon Basin (abstract) ; by < '. W. Hayes . . . 495

< reology of the Pribilof Islands; by .!. Stanle\ -I'.rown

Session of Thursday, December :;i 500

The Gulf of Mexico as a Measure of Csostasy (abstract); by W.I McGee... 501
Supposed interglacial Shell-beds in Shropshire, England ; b; <i. F. Wright. 505

The ( ihamplain Submergence (abstraci i ; by Wan-en Dphano

Note on the Middleton Formation of Tennessee, Mississippi and Alabama ;

by .1. M. Safford ;,i I

PaleasU r 1 ucharis ; by A. II. ( !ole 512

On the Structure and ige of the Stockbridge Limestone in the Vermonl

Valley; by T. X. Dale .,14

I Contribution to the Geologj oftheGreal Plains; by Robert llav 519

List of Officers and Fellows of the < reological Society of America ."»•_•:;

Index to Volume •'! ;,:;i

I.X 1 1 lii 1 1 i,i mi --m,, . \ m.. Vol. 3, lfl 15

454 PROCEEDINGS OF COLUMBUS MEETING.

Session of Tuesday, Decembee 29.

The Society met in the Hall of Representatives, State House; Acting
President G. K. Gilbert presiding during the meeting. After the call to
order at 10.15 a. m. and a few words of salutation, the Acting President
introduced the Mayor of the city of Columbus, Honorable George J.
Karl), who made a brief hut cordial address of welcome, to which
response was made by the Acting President.

Announcement was made that the report of the Council would be
deferred until Wednesday morning.

The report of the Treasurer was presented in abstract by the Secretary.
It showed a balance in the treasury, when the sum of $859.74 belonging
to the permanent fund is deducted, of $280.74.

The Society elected as an auditing committee Messrs J. C. Smock and
J. S. Diller. '

ELECTION OF OFFICERS AND FELLOWS.

The result of the balloting for Officers. Fellows and amendment to the
Constitution, as canvassed by the Council, was declared by the Secretary
as follows :

OFFICERS ELECTED FOR ISO!.

Preside i ti :
G. K. Gilbert. Washington. D. C.

Vice-Presidents:

Sir J. William Dawson, Montreal, Canada.
T. C. Cham berlin, Madison, Wis.

Secretary :
H. L. Fairchild, Rochester, N. Y.

Treasurer:
I. C. White, Morgantown, W. Va,

Councillors, Class of 1894:
H. S. Williams, Ithaca, N. Y.
X. H. Winchell, Minneapolis, Minn.

Editor :
W -I McGee, Washington. 1). C.

MEMORIAL OF J. FRANCIS WILLIAMS. 455

FELLOWS ELECTED.

Garry Eugene Culver, A. "SI., Vermillion, S. Dak. Professor of geology, Univer-
sity of South Dakota; now engaged in artesian and underflow investigation of
the Unite' 1 States Department of Agriculture.

Henry Gannett, S. B., A. Met. B., Washington, D. C. In charge of geographic
work of the United States Geological Survey east of the 100th meridian.

The proposed amendment to the Constitution, making the Treasurer
eligible to reelection without limitation, failed for lack of three-fourths
affirmative vote of the total membership.

A memorial of J. Francis Williams, prepared by J. F. Kemp, was
read by the Secretary :

MEMORIAL OF JOHN FRANCIS WILLIAMS.

The name of Dr. J. F. Williams will always be associated in American
geology with those of Newton, Irving and Lewis. His life, like theirs
was one of brilliant achievement, of great future promise, and of sad,
untimely termination. Although his accomplished results were great,
yet, coming as they did early in life, his friends could but regard them
as indicative of the future, and there is thus, together with grief for bis
loss, the regret that so many possibilities are nullified. As he was one
of the thirteen original Fellows who gathered at Ithaca in December,
1888, and organized the Geological Society of America, it is eminently
fitting that some especial memorial of him should be presented.

John Francis Williams was born October 25, 1862, at Salem, the county
seat of Washington county, New York, situated about forty miles north-
east of Troy. He was the only son of John Martin and Frances A.
(Schriver) Williams, who, with bis one sister, survive him. His boy-
hood was passed at the beautiful family home until at twelve years he
was placed in Saint Pauls School, Concord, New Hampshire. Leaving
this in L880, he entered the Rensselaer Polytechnic Institute at Troy.
He completed (he studies of the course in civil engineering and gradu-
ated in L883 with the degree of C. E. Thus, like many geologists, he
began his scientific work in the engineering school, hut found his tastes
inclining irresistibly to pure, as contrasted with applied, science. Al-
though during August of L883 he was assistant engineer of the Albany,
Rutland and Granville railroad, in the following autumn he became
assistanl in chemistry and natural science at his alma, mater, lie was
broughl in especially close association with his teacher and warm per-
sonal friend. Professor Henry B. Nason, whose influence was largely
instrumental in shaping Ids subsequenl career. During this period lie

456 PROCEEDINGS OF COLUMBUS MEETING.

made the tests of slates from the region about his home, the publication
of which is subsequently cited. The Rensselaer Polytechnic Institute
conferred on him in 1885 the further degree of B. S.

In the summer of 1884 he traveled in northern Europe, visiting North
cape and the mines of Sweden and Norway. In the fall, acting on the
advice of Professor Nason,he matriculated at the university of Gottingen
and became one in a long and honorable list of American scientific men
who have received their preparation at this ancient seat of learning.
While at Gottingen his work lay especially in mineralogy and petrog-
raphy under the guidance of Professor Carl Klein, now of Berlin, and in
chemistry under Professor Victor Meyer.

In the spring vacation of 1885 he traveled with Professor Klein through
Italy and Sicily, and later was assigned the subject of his doctor's thesis
in one of the extinct volcanic districts of the former. Through Professor
Klein, Dr. Williams came to know Professor Rosenbusch, of Heidelberg,
to whose kind advice he was afterward indebted in his American work.
Professor Klein received in Sienna several specimens of an igneous rock
from Monte Amiata, an extinct volcanic pile that rises near the classic-
lake Trasimenus and forms the highest peak in Tuscany. The}7 proved
of such interest that they were intrusted to Dr. Williams as suggestive
for his thesis. With characteristic energy and thoroughness he pro-
ceeded to the region in September, 1885, and, accompanied by a Swiss
helper and a local Italian guide, he spent several weeks on the moun-
tain, either camping or lodging in the little Italian inns.

Returning to Gottingen, he anticipated taking his doctorate in the
summer of 1886, but the sudden call of Professor Klein to Berlin neces-
sitated holding the examinations in the spring. He received his degree

igna cum laude. The thesis was afterward published in the NeuesJahr-
buch, and gained great praise in America as well as abroad. The paper
is accompanied by four partial and twenty-two complete analyses of
rocks, by an elaborate geological map. and by three panoramic views.
Its special interest lies in the fact that it traces the differences in rock
types throughout one great single eruptive mass, which is shown in its
central part to be a trachyte containing hypersthene and labradorite,
but which passes toward the borders sometimes into liparite, sometimes
into andesite.

Professor Klein desired Dr. Williams to go to Berlin, become his as-
ant. and continue his career in Germany. For a time in 1886, this
course was followed, but finally Dr. Williams returned to his home, and
in 1887 became director of the technical museum of the Pratt Institute
in Brooklyn. The duties consisted in arranging excellent collections of
minerals and rocks, but the desire for wider opportunities tor scientific

MEMORIALS OF J. FRANCIS WILLIAMS. 457

investigation led him in 1889 to take the position of honorary fellow at
Clark university, Worcester. While in this relation he received over-
tures from Professor J. C. Branner which led to his undertaking the de-
scription of the igneous rocks of Arkansas. Dr. Williams secured leave
of absence from Clark and entered on his Arkansas work as a volunteer
without salary in October, 1889. In the summer of 1890 he was made
honorary docent at (lark university. This title, like his previous one,
carried no salary with it, and merely afforded him a work-room and
headquarters. Dr. Williams gave some lectures on crystallography to
chemists during one or two months in the spring, and for this purpose
furnished his own models, diagrams, etc, and even loaned his own goni-
ometer to the chemical department of the university for whatever meas-
urements were made on crystallized salts.

Dr. Williams found a wealth of interesting material in Arkansas, and
as the result of his collecting published in 1890 the papers on mangano-
pectolite and eudialyte cited below. In the fall of 1890 he returned to
Arkansas and completed his work, remaining, except for one or two trips
home, until the summer of 1891. He had meantime accumulated the
observations for his final and greatest work, which forms volume ii of
the annual report of the Arkansas geological survey, and is entitled
"Igneous Rocks of Arkansas." The volume, which is just distributed,
contains 432 pages, 391 of which are by Dr. Williams alone, and which
uive an accurate and exhaustive petrographic description of the syenites
eleolite-syenites and leucite-syenites, the variations of all three, and the
basic dikes which pierce them. Perhaps the greatest interest lies in the
identification of leucite in these rocks and in the establishment of Creta-
ceous leucite-syenites as a new variety. This opposes the generally held
but quite unwarranted belief that leucite is limited to the later volcanic
rocks. The report is accompanied by beautifully executed topographic,
maps and by many other illustrations. Much of its success was made
possible by the cordial and efficient support given Dr. Williams by Pro-
fessor Branner, but it bears on every page the marks of tireless and pains-
taking scholarship. Professor Branner in the preface bears testimony to
the enthusiasm and energy with which Dr. Williams carried it through,
mid the writer of this memorial, who was associated in some minor por-
tions of the work, can witness also to his consuming interest in his work.
Dr. Williams was appointed assistant geologisl Oil the survey in 1891,
and in this official capacity his name appears on the title page of the
report. In L 891, in connection with Dr. Et. N. Brackett, he carried on
investigations in certain minerals of the Kaolin group, which appeared
in the American Journal of Science in July last.

458 PROCEEDINGS OF COLUMBUS MEETING.

In June, 1891, the position of assistant professor of geology and min-
eralogy became vacant at Cornell university, and Dr. Williams was called
to the chair. He accepted, and alter making the western excursion of
the International Geological Congress, he attempted to take up his duties,
hut weakness and disease were already laying a heavy grasp upon him.
A severe attack of the so-called "grip "in March last had sapped his
strength, and ill-advised methods of work had aggravated its results-
Dr. Williams worked well but not wisely, and, led away by interest in
his subject, protracted his labors until 2 and 3 o'clock in the morning.
These habits are specially injurious in Arkansas, and gave his friends
great anxiety. At last he became but the shadow of himself — the strain
upon him was too severe and his constitution finally yielded. Paralysis
attacked him, and after an illness of about two weeks he passed away
on November 9, being just 29 years of age.

It has never been the lot of the writer to know intimately a more
generous, frank and lovable man than J. Francis Williams, and it is
impossible to speak of him without the deepest emotion. His character
was such as to indescribably endear him to his friends, and his abilities
and preparation for his work were of the highest order. His results
were such as to secure for him in all the future one of the most honor-
able places in the records of American geological science.

A list of Dr. Williams' published papers is appended:

Tests of Rutland and Washington County Slates : Van Nostrand's Engineering Mag-
azine, no. clxxxviii, 1884, pp. 101-103.

Ueber den Monte Amiata in Toscana und seine < resteine : Neues Jahrbuch, Beilage
Band v, L887, Seiten :;si-4">0 u. Tafeln xiii-xvi.

Manganopektolith, ein neues Pektolith-ahriliches Mineral von Magnet Cove, Ar-
kansas: Zeitschriftfur Krystallographie, B. xviii, 1890, S. 386.

Eudialyte and Eucolite from Magnet Cove, Arkansas: .1///. Joum. Sci., 3d series,

vol. xl, 1890, pp. 457-462.
Tests of some Arkansas Syenites: Railroad and Engineering Journal, vol. Ixv, 1891,

p. 13.
Newtonite and Rectorite, two new Minerals of the Kaplinite Group (by R. X.

Brackett and .!. Francis Williams): Am. Joum. Sci., 3d series, vol. xlii, 1891, pp.

11-21.

Annual Repoi't Geological Survey of Arkansas, 1890, vol. Li: The Igneous Rocks of
Arkansas, pp. 457, and maps.

J. F. K.

Mr. J. S. Diller, for the ( !ommittee on Photographs, made an oral report,
stating that nearly three hundred new photographs were received since
the last report and were on exhibition.

I. C. WHITE — FOSSIL PLANTS FROM THE WICHITA. 4")9

The reading of papers was declared in order, and the lirsl paper on the
printed program was announced, entitled —

THE MANNINGTON OIL FIELD AND THE HISTORY OF ITS DEVELOPMENT.

BY I. r. WHITE.

Remarks were offered by G. K. Gilbert, Arthur Winslow and E. W-
Claypole. The paper forms pages 187-216, with plate •', of this volume.

The second paper was —

FOSSIL PLANTS FROM THE WICHITA OR PERMIAN FEDS OF TEXAS.

BY r. C. WHITE.

In the subsequent discussion remarks in confirmation of the Permian
age of the Wichita beds were made by several Fellows. Professor E. W.
Claypole observed —

There is much to be said in favor of an American Permian, though there is con-
siderable prejudice against the Permian on the pari of some American geologists. I
do not regard the finding of trilobites as an objection.

Professor Alpheus Hyatt said :

I have found the cephalopod fauna of the beds described by Professor White

to he decidedly Permian.

In reply to a question, the author said the plant fossils of the American
Permian were of fresh-water origin. Mr. E. T. Dumble remarked :

The plants sent to Professor White were taken principally from the Wichita
beds, the lowest nf the three divisions into which the Permian formation of Texas
has been separated; The Walchia, however, is not confined to this division, but
occurs also in the sandstone of the overlying Clear Fork beds. These plants occur
in the beds in which are found the invertebrate forms described by Dr. ( '. A. White
and which contain such characteristic Permian fossils as Medlicottiu. These Tonus
were examined by the Russian geologists at Washington during the meeting of the
International Geological Congress, and were pronounced by them identical with
the species found in the Permian of thai country. The vertebrate forms described
by Professor Cope as I 'em nan were obtained also from the Wichita division.

The paper is printed on pages 217-218 of (his volume.

A recess was voted until '_' o'clock.

4<)0 PROCEEDINGS OP COLUMBUS MEETING.

On reassembling at 2 o'clock p. ra. the following paper was read :

GEOLOGY OF THE TAYLORVILLE REGION OF CALIFORNIA : PART I — THE

GEOLOGIC COLUMN.

BY J. S. DILLER.

This was immediately followed by —

JURA AND TRIAS AT TAYLORVILLE, CALIFORNIA.
BY ALPHEUS HYATT.

The two papers were discussed by E. W. Claypole, W. H. Pettec. I. ('.
White and G. K. Gilbert,

The next paper was a continuation of one of the preceding :

GEOLOGY OF THE TAYLORVILLE REGION OF CALIFORNIA : PART II —

STRUCTURE.

BY J. S. DILLER.

The three papers are printed as pages 369-412 of this volume.

In the absence of the author, the following paper was read in abstract
by C. Willard Hayes :

STRATIGRAPHY AND SUCCESSION OF THE ROCKS OF THE SIERRA NEVADA

OF CALIFORNIA.

BY JAMES E. MILLS.

This communication was discussed by G. K. Gilbert, C. W. Hayes and
J. 8. Diller. It forms pages 413-444, with plate 13 of this volume.

The following paper was read by J. S. Diller, the author not being
present :

SECONDARY BANDING IN GNEISS.*
BY WM. II. ITOBBS.

The fact that secondary cleavage or foliation is to he found in the schistose rocks
of Berkshire county, Massachusetts, is mentioned by Dana in his papers on the
geology of the region. The extent to which it is developed and the importance of
carefully distinguishing it from planes of stratification in the working out of geo-
logic structure was first emphasized in the study of the Greylock group by the

♦ Published by permission of the Director of (lie Pnite<l States GoolntjicMl Survey.

CO
CO

DC
<
Q

o
o

LlI
CO

W. II. HOBBS — SECONDARY BANDING IN GNEISS.

4< 51

Archean division of the United states Geological Survey, in charge of Professor
Raphael Pumpelly. Mr. T. Nelson Dale, assistant geologist, lias prepared a mono-
graph on mount Greylock, in connection with which he has made an extensive
study of secondary foliation* A summary of his conclusions is contained in the
American Geologist for July, 1891. t

The rock exposure illustrating the peculiar structural feature which forms the
subject of this paper is located east of the village of Great Barrington, near the
Hopkins-Searles dolomite quarry. The locality has already received considerable
attention from geologists. Professor Dana, in his first series of papers on the geology
of Berkshire county ,| printed a section passing through the locality, at which the
apparent unconformity of the limestone and gneiss was explained by a fault. The
portion of the section in question was printed on a larger scale as "section number
25 '* of Ins paper on Taconic rocks and stratigraphy.^ Tins is reproduced in figure 1 •

Figure 1. — Section near Great Barrington (after Dana).

Julien, in a paper entitled "On the Geology at Great Barrington, Massachu-
sctts," || has described the same locality. Mis views of the geologic structure are
expressed in figure 2.

-yd*/ ii

s, schi'bb or gneiss. q,q_uarUytc
d* d* clolomyfce. a , an- e-n-cieivt fault
Jo, 111. o f e 1-fcceii-t fa-ult.

Figure 2. — Section near Great Barrington (pftei Julien).

Mr. T. Nelson Dale,!] assistanl geologisl in the Archean division of the United
states Geological Survey, visited the Searles-Hopkins quarry al Great Barrington
on October 5 and 14, L889, and Mr. J. !•'. Wolff examined the gneiss later microscop-

*Now in the hands of tlie public printer at Washington.

I l'h' Grej lock Synclinorium : \m. Geol., vol. \ iii, pp. l-T.

[ On the Quartzite, Limestone and Associated Ro -k- of the vicinity of Gri i( Barrington, B
shire eonnty, M if \m. Journ. Sci., 3d series, vol. v, 1873, p. 26, fig. 7.

g On Taconic Bo lis and Stratigraphy, with i logical Map ol the Taconic Region : Vm. Journ.

Sci., 3d Beries, vol. \ \ \iii, 1887, p. WO, with plate 1 1 .
Trans New Ifork Acad. 8ci., vol. v, 1887, p

• i hi p ii i j i imIi and the ai npanying figure "■ were prepared for this paper by Mr. Pale.

I.\ III Bui.ii, '■>.,,,. Soi . \m.. Vol .3 1891,

162

PROCEEDINGS OF COLUMBUS MEETING.

ically. In Mr. Dale's report to Professor Raphael Pumpelly, United States geolo-
gist, dated March, 1890, he described the locality in the following words :

••East of Great Barrington, at the Searles-Hopkins quarry, a rather coarse-grained muscovite
biotite gneiss is in contact with a micaceous pyritiferous dolomite. An analysis of the dolomite is
given by Mr. A. A. Julien in his paper on the geoiogy of Great Barrington (Trans-art ions of tin .V u
York Academy of Science, vol. v, 1887, page :;7). The plicated stratification planes of the gneiss dip
at th'- contact r;n0-4(i0 west, and westerly dips occur also along the steep part of tin.' base Of mount
Keith, both north and south of the quarry, hot the gneiss on the hill due south of the reservoir has
a stratification dip only a tew degrees east or west of 90°. The cleavage-foliation dip at the quarry
is. however. 60° east. The relations of tie' stratification-foliation to the cleavage-foliation are shown
in the accompanying sketch, made from a specimen. The general relations of stratification and
cleavage in the schists of Berkshire county were set forth in my report on the areal and structural
geology of mount Greylock."

U S.CeOuOClCM. SuRvKY

SHEFntlt* •S-hEET

ClTea t square Fool.

"Plicated Quart* veins and cleavage
FoliaCton uxnUiscavite-BiotiXc- 6nfciv5

near Hof>Kiu% QuanTY, Great .Barri.nqG)n

1na>-cK imp ' B3te

Figure '■'>. — Cleavagt ami Bi'lnimj near Great Barrington (after Dale).

The Hopkins-Searles quarry lies very near the line separating the portions of
territory allotted to Mr. Dale and myself fur study. Ignorant of the fact that he
had examined the locality, I visited it in July, 1890, and arrived at the same con-
clusions concerning the general structural relations that he had reached in the
previous season. Figure 4 shows the probable relations at the quarry.4*

1 200

15oloUTi.be Giifcisl,-

1 1 oo:

jImc\ ' Spi-in^

120 0'
-I ioo'

I oou'
_9oo'

8oo

8oo'

Sc.aL^ ["- 5 2 8'
Figure 4. — Structure of Hopkins-Searles Quarry.

* A uniformly easterly cleavage-foliation exists also in the schist west of the Great Barrington
valley, where it corresponds more or less closely in direction with the bedding plane.

\V. II. HOBBS — SECONDARY BANDING IN GNEISS. 463

The gneiss is mainly composed of quart/., feldspar and mica, and effervesces
slightly with acid. Thin sections show that it contains rather more muscovite than
biotite, and, as accessory minerals, zircon and magnetite. The dip of the dolomite
in the southern part of the quarry is 60°-70° west, and the strike about north 15°
west. Corresponding dips occur in the northern quarry. In ascending the hill the
gneiss is first met with at the spring (about 50 feet from the upper edge of the
quarry). Besides a cleavage-foliation (60°-70° east), the gneiss shows a marked
straight banding, the direction of which is the same as the foliation. No other struc-
ture than these two was discovered. A few paces above the spring an opening has
been made in the gneiss by a small quarry, and a similar opening has been made
about 100 feet farther northward. Here the mass of the rock is fresher and shows
the same structure as that at the spring, with the exception that much contorted
lenses of quartz clearly show the position of an earlier structure-plane, which now
has an average dip of 40° west, with steeper dips on the west and lower dips on the
cast. Locally other evidences of this structure can be made out, namely, a crumpled
banding having the same direction as the contorted quartz lenses. On the northern
wall of the more northerly of the two quarries this structure is brought out in great
perfection* The strike of the cleavage-foliation at this locality is north 15° west ;
the bedding-plane appears to strike about north 9° west. With the assistance of a
skilled stone-worker, a hloek of gneiss was cut from this spot so as to have it.- face
approximately perpendicular to the strike. The dimensions of the face of the hloek
were about two feet by one and its thickness about a foot. This block has been
sawed twice through parallel to its face and the plane surfaces of the slabs carefully
smoothed. One surface of the middle slab also has been given a polish. A photo-
graph of this surface is reproduced in plate 14.

The unique feature of this specimen does not consist in the crumpled bands, the
contorted quartz lenses, or the cleavage foliation, all these having been observed
in other localities in Berkshire county ,f though it is doubtful if the three structures
have been observed together in such perfection as at this locality. The novel
feature is the secondary straight banding parallel to the induced foliation. This
banding is due to an alternation of layers of different mineral composition, which
gives the structure an appearance very like that of ordinary sedimentation. The
white bands are composed mainly of quartz and feldspar, the dark ones of mica.
These bands no doubt date from the same period and were produced by the action
of the same forces as the foliation. As already stated, the straighl banding and
foliation are the prevailing structures at the locality, the crumpled banding being
observed only al a few localities; and it is noticeable thai at these localities the
straighl banding dies out alto-ether as it meets the series of crumpled bands, to
recur again on the other side of them, as indicated in plate 1 1.

The occurrence of parallel layers of different mineralogical composition in a meta-
morphosed elastic rock has been considered one of the besl criteria in determining
i he planes of stratification, where these have 1" 'en partially effaced by subsequently
induced structures. The structures observed in the gneiss of the Elopkins-Searles
quarry indicate thai one may easily be deceive 1 in applying this principle.

Kxn.w \ i I0S OP Platj 11

The plate shows u polished slab of ealcar is muscovite biotite gneiss from near the Hopkins-

rli - dolomite quarry at Great Barrington, Massachusetts, ["he size of the bou.t 2 feet bj

1 1 i- :ii-., well marked .i little way north of the quarry in a low led id can also be

perfection, in blocks m found in the southern quarry,

I lale, "i

4(34 PROCEEDINGS OF COLUMBUS MEETING.

1 foot. A well developed cleavage-foliation runs parallel to tin' side on which the block rests. In
.1.1 and A' A' a. nearly straight secondary banding follows this direction. At BD this banding is
completely replaced by a crumpled transverse banding, showing the present position of the origi-
nal st rati Heat ion plane. At CC the course of a crumpled quartz lens can be followed parallel to that
of the crumpled banding.

In discussing the paper Dr. J. E. Wolff remarked —

There is a similar example on a large scale in the rnetamorphic conglomerate
series at East Clarendon, near Rutland, Vermont. The rock has a vertical hand-
ing and foliation, and the hands, being of different mineral composition, might be
taken for stratification, were there not present occasional bands of pebbles with an
undulating horizontal course which indicate the original stratification, while the
individual pebbles have their major axes turned so as to lie in the plane of vertical
banding and are somewhat stretched in that plane.

The next paper was read by Professor C. \Y. Hall :

PALEOZOIC FORMATIONS OF SOUTHEASTERN MINNESOTA.

BY ('. \V. HALL AMI F. \V. SARDESOX.

In discussing the paper \V J McGee remarked —

There is some confusion in the nomenclature of the scries of upper Cambrian
and basal Silurian strata so admirably described by the authors of this communi-
cation. While there tire local and inconstant unconformities, the series as a whole
is a continuous one connecting the Cambrian and Silurian. This series is relatively
complex in Minnesota and still more complex in Wisconsin, hut relatively simple
in Iowa; and in the areas of complex structure, divisions have been discriminated
that are lost in the areas of simple structure. Moreover, Owen's name " Lower
Magnesian " has become misleading since his correlative term " Upper Magnesian "
(including the Niagara and Galena and by implication the intervening Maquoketa)
has been dropped from geologic language and literature. Partly for these reasons.
the Iowa representative of Owen's "Lower Magnesian," which corresponds to
living's a Main Body of Limestone," has been called Oneota limestone from the
river on which the formation is typically developed.*

Professor Hall replied :

While a certain degree of confusion attaches to the use of Owen's term "Lower
Magnesian" for the rocks in question, that confusion disappears when the first
element in the name is dropped. "Magnesian" is at the same time a convenient
name and possesses the advantages of accurately describing the lithologic and
chemical characters of the great mass of dolomite to which it is applied, and of
closely corresponding to the original designation which has taken an established
place in geologic literature. Indeed the word has become so well fixed in the
northwest that we can use it with ease, notwithstanding the advances already
made in our knowledge of the rocks included under it. It is the intention of the
authors to continue their studies of these strata, discussed in barest outline in the

*lltli Ann. Rep. U S. Geological Survey, 1892, p. 332.

HALL AND SARDESON — PALEOZOIC FORMATIONS. 465

paper presented, and to discover everything they can touching their lithologie and
paleontologic characters. The interesting results which have already attended
their explorations of the Saint Peter sandstone give great encouragement that
something of interest will be developed by a careful and systematic study of the
rocks underlying that horizon. When their paleontologic investigations shall be
well advanced it may be that a name of some real paleontologic significance can
be attached to these rocks in place of the lithologie one now in such universal use.
Certainly the retention for the present of the old name cannot add any confusion
to nomenclature. The position taken by Mr. McGee is appreciated, and the name
proposed by him in Iowa, Oneota limestone, may yet prove to be the best one to
adopt for Minnesota and Wisconsin.

The paper with its illustrations is published as pages ool-ob<S, with
plates 10-12 of tins volume.

After announcements from the Chair concerning the evening session
the Society adjourned.

Evening Session ok Tuesday, Decembeb 29.

The Society was called to order at 7.30 p. m. and a lecture was deliv-
ered on —

MOUNT ST. ELIAS .VXD ITS GLACIERS.
BY [SBAEL C. RUSSELL.

Tlio Lecture was illustrated by maps and lantern views. Remarks
wen- made in discussion of the subject by G. F. Wright. G. K. Gilbert
and others.

Following the lecture by Mr. Russell, Dr. J. E. Wolff exhibited and de-
scribed a scries of lantern views illustrating a paper on the Crazy moun-
tains, to be read at a Later session.

The Presidenl made announcements and the Society adjourned. After
adjournmenl an informal reception was given the Society and the Ohio
State College Association by the local Reception Committee. Uriel' -m\-
(\rt'<-<f< were made by Rev. Dr. Bashford, Mr. Gilbert and Professor
Kellicott.

466 PROCEEDINGS OF COLUMBUS MEETING.

Session of Wednesday, December 30.

The Society was called to order at 10 o'clock a. in. by President Gil-
bert.

The Council report, deferred from the preceding day. was declared in
order and was read by the Secretary as follows:

REPORT OF THE COUNCIL.

To the Fellows of the Geological Society of America,

in Fourth Annual Meeting, 1891:

The Council congratulates the Society on the prosperity and success
of its third year. The record is one of growth, prosperity and achieve-
ment. The Society lias now drawn into itself, speaking not too broadly,
the geologists of the continent, and a fine spirit of loyalty and of good-
fellowship has been shown among its members. As the only geological
association in America, and perhaps the only society in existence re-
stricted to working geologists, every Fellow should feel a just pride and
a personal responsibility in the success of the Society.

Meetings of the Council. — Since the last report was made the Council has
held four meetings ; two of them with two sessions. One was held at the
close of the winter meeting, one in April, one preceding, and one during
the summer meeting; all of them being in Washington. The attendance
was large, and an earnest effort has been made to promote the interests
of the Society.

Meetings of f/u Society. — The records of the two meetings held since the
last report will be found in the printed proceedings. At the winter meet-
ing the registered attendance was sixty-six. and at the summer meeting
eighty-three. Considering the great area over which the membership is
distributed it is a matter of congratulation that the attendance has been
so large, as indicating the vigor of the Society and the interest of the
Fellows.

Membership. — During the past year the Society has suffered loss by the
death of President Winchell and of J. Francis Williams and by one
resignation. At the summer meeting thirteen men were elected. The
roll now includes the names of two hundred and thirteen Fellows, to
which should be added the names of the two Fellows declared elected at
this meeting.

Five Fellows are so in arrears for dues that unless payment is made
before January their names must be erased from the roll under the rules
i By-Laws, chap. 1. sec. 3).

The Council will soon nominate for Correspondents several eminent

REPORT OP ttii: COUNCIL. 467

foreign geologists. Their election will involve the presentation of as
many copies of the Bulletin.

Bulletin Publication. — The first part of volume 3, the proceedings of
the summer meeting, will soon be ready for distribution, having been
delayed by unusual circumstances. It lias been decided to limit the
volume to five hundred pages.

The'" Rules Relating to Publication," which were mailed to tin- Fellows
previous to the summer meeting, formulate the legislation of the Society
and Council upon the whole matter of the Bulletin and embody the
teaching of experience up to this time.

Bulletin Distribution. — The brochures of volumes 1 and "_' were dis-
tributed to the Fellows directly from Washington with many losses. These
deficiencies have been made good to the Fellows as far as known, being
supplied from the reserve stock. Henceforth the entire distribution of
the Bulletin will he from the Secretary's office, and care will be taken to
distribute promptly and without loss.

The disposition of the surplus stock of volumes 1 and 2 is shown in
the following table :

Bulletin Distribution from tlu Secretary's Office January, 1891, to January, 1893.

BY COMPLETE VOLUMES.

Vol. I. Vol. ■>.

Held in reserve i:;s 393

Donated to institutions ("exchanges") 7:: 7:;

Held for " exchanges " 19 in

Scut to Fellows to supply deficiencies 2 1

Sold tu Fellows 7 •">

Sold to Libraries 21 21

Donated by direction of Council :! .".

Bound for office use 1 1

Number of complete copies received 264 510

BY BROCHURES.

Vol. l. Vol. 2.

. . . - I, . , i ,. ■ f (to 4 Fellows) :'>•'!

>«'iil tn rclliius to supply deficiencies . . ,. ,- ,, .,

1 ' ■ Mini/ Fellows) 63

Sold tn Fellows :> 2

n„ijj i- n f (to 1 person i I

sold tn in m-rellows to i-

i (to 8 persons) to

Total 39 so

There remains a considerable stock of extra brochures which cannol
be foliated into volumes.

Hull, I'm Sales.- It was nol deemed advisable to advertise the Bulletin
until its character and nermanence were established. The condition has

408 PROCEEDINGS OF COLUMBUS MEETING.

now been reached where it is proper and feasible to seek some income
from the publication. The Fellows are again requested to use their in-
fluence toward the sale of the Bulletin to libraries by permanent sub-
scription. Through the recent efforts of the Fellows, twenty-five libraries
have subscribed.

The sale of the Bulletin to date is itemized in the preceding and the
following tables :

\—

Receipts from Sale of Bulletin, January, 1891, to January, 1892.

BY SALE <>I" COMPLETE VOLUMES.

Vol.1. Vol.2. Total.

From Fellows $35 10 $22 50 $57 60

From libraries 80 00 80 00 160 00

Total $115 10 $102 50 $217 60

BY SALE OF BROCHURES.

Vol. 1. Vol. -1. Total.

From Fellows $2 75 $2 75

From non-Fellows 40 $4 95 5 35

Total $3 1 5 S4 95 $8 10

Total receipts $225 70

Due and not collected for five sets and two brochures 50 45

Grand total from sales $276 15

There has been paid in advance for volume 3 the sum of $15.

Bulletin Donations (" Exchanges " ). — At the beginning of the year a small
list had been made of societies and institutions to which it was proposed
to donate the Bulletin, authority having been given the Council at the
New York meeting. This list was afterward extended and a circular
letter was sent to the addresses. The two volumes have been sent to all
the addresses which responded to that letter, sixty-eight in all. distributed
as follows : United States, 12 ; British America, 5 ; South America, 1 :
Great Britain and Ireland, 7 ; Europe, 32 ; Asia, 3; Australasia.*); Ha-
waiian islands. 1 ; Africa. 1. To five other addresses the volumes have
been sent in anticipation of replies to the letter. In this matter the desire
of the Council has been to place the Bulletin where it will be the most
useful, rather than to seek a return in kind.

Exchange Product {Library). — It is certain that many institutions re-
ceiving the Bulletin will desire and expect to send their publications in
return, and the Society is sure to be the recipient of much printed matter
from many sources. Some material has already been received, in addi-
tion to the photographs, manuscripts, books, etc. collected by Professor

REPORT OF THE COUNCIL. 169

Hitchcock with permission of the Council. With no home or perma-
nent location for the Society, the proper disposition of library material
has been a problem. The result of the consideration of this question is
a prevailing sentiment in favor of depositing the Society's library in some
institution where it may be useful to the Fellows of the Society who are
far removed from the greal libraries of the eastern states. I>y authority
of the ( Jouncil the Secretary has held correspondence with several coll< a
and libraries with the result that offers are now before us to receive the
material on deposit under conditions which relieve the Society from all
expense, even for binding, while retaining full ownership.

Finances. — The available incomeof the Societyis limited to the annual
dues and the inconsiderable interest from an investment of Less than
$1,200. This is barely sufficient to pay the cost of economical adminis-
tration and of a volume not expensively illustrated.

The cost of volumes 1 and 2 is shown in the following tabulation :

' OST o|' BULLETIX.

., . . Vol.1. Vol.2.

( OSt tO the Society: pp.593; pi. 13 J (pp.662;PI.23.)

Letterpress ) 81,367 77 $1,935 27

I llustrations 291 85 302 35

Total $1,659 62 $2,237 62

Cost to Authors :

Illustrations §161 30

Corrections..*. §38 00 27 25

Brochure covers 68 00 30 00

Total $106 00 $218 55

Aggregate $1,765 62 $2;456 1 7

fellows are urgently requested to assist in increasing the Society's in-
come and to establish a publication fund. The securing of subscriptions
to the Bulletin is a reliable help, even if not large. The Council desires
to repeal the demand for $10,000 as a fund for publication.

Recommendations. — The Council makes the following recommenda-
tions :

1. That the Council be authorized to increase the list of " exchangi
if deemed desirable, to a number not to exceed one hundred.

•J. That the Council be authorized to deposit the library material ac-
quired by the Society iii sonic institution, under terms which shall leave
the Society in absolute ownership.

.'!. That in recognition of his services to the Society Dr. J. J. Stevenson

lie elected ;i Life Member, W'itll dlle- remitted.
LXIV I'.i 11 . ' 9oi , Am.. Y.. 1 . .. 1891

■•

470 PROCEEDINGS OF COLUMBUS MEETING.

The report of the Council was received, and the three recommenda-
tions were adopted by formal vote.

The proposed amendment to the By-Laws was taken from the table.
During debate, remarks were made by several Fellows. An amendment
to the amendment was offered by Professor Pettee, which was adopted;
and the amendment, to read as follows, was adopted unanimously:

'■ Chapter ii. Article 7: The Council may transact its business by cor-
respondence during the intervals between its stated meetings ; but affirm-
ative action of a majority of the Council shall be necessary in order to
make action by correspondence valid."

The Auditing Committee reported the accounts of the Treasurer cor-
rect. The report was adopted.

The Committee on Photographs made a formal report, which was
adopted. It was voted that the committee he continued, and the unex-
pended balance of the appropriation he available for the coming year.
The report is as follows :

SECOND ANNUAL REPORT OF THE COMMITTEE ON PHOTOGRAPHS.

The total number of photographs now in the collection of the Geological Society
is 635. Last year the collection reached 293. This year 1342 photographs have
beenadded to the collection by the donors whose names appear in the register.
When duplicate photographs are desired, application should in all eases be made
directly to the individual who presented the photographs to the Society.

Some of these views, together with those collected last year, were exhibited in
Washington at the summer meeting of the < Geological Society and at the American
session of the International Geological Congress. All of the views received this
year, excepting those presented by the < Jeological Survey of Canada, were exhibited
at the Columbus meeting.

The collection is now at the office of the United States Geological Survey in
Washington. D. ('.. in charge of the Washington member of the committee, where
it is readily accessible to Fellows for examination.

The expenses of the committee during the year in collecting the photographs
temporarily binding them, and preparing them for exhibition, were $9.83.

The committee solicit the donation of good photographs which clearly illustrate
important geologic phenomena. They may he sent to any member of the com-
mittee at the following addresses: Professor J. F. Kemp, Columbia College, Xew
York city; Professor W. M. Davis, Harvard College, Cambridge, Mass.; Mr. J. S.
Diller, I". S. Geological Survey. Washington, D. C.

Prints smaller than 4 x 4j inches arc not desired. All prints should be mounted :
and for artistic effect, as well as ease of preservation, gray cards are preferred.

Each photograph should be plainly labeled, either on card or plate, giving the
subject, with a brief but explicit reference to what is illustrated by the photograph,
its date, locality, name of the artist and donor, and a reference to its publication, if
the photograph has been published. The label should he placed, if in type, on the
front beneath the photograph ; if in script, on the back.

REPORT OF COMMITTEE OX PHOTOGRAPHS. 471

The photographs should be accompanied by a statement whether duplicates and
lantern-slides can be obtained, and at what price, and the address of the person to
whom application for them should be made. It is suggested that in order to save
trouble to donor, arrangements be made with local photographers to whom the
negatives may be entrusted to till orders.

Initials in parentheses at the end of labels indicates authorship within the com-
mittee.

Photographed and Presented by Dr. G. II. Williams, of Johns Hopkins University, Bal-
timore, Md.

Size, about 4j x (U inches. Photographs of laboratory specimens.

294. Appalachian structure: anticlinal fold running into a synclinal; Cumber-

land, Md.

295. Anticlinal fold ; Animikee slate. Pigeon point, lake Superior.

296. Folded Halla-flinta; Naerodal, Norway.

297. Gneiss; Stony Point-on-the-Hudson, N. Y.

298. Slate, showing bedding, cleavage and rigid calcareous layer; Bangor, Pa.

299. Quartz-schist, with stretched tourmaline; Shoemaker's quarry, Green Spring

valley, Baltimore' co.. Md.

300. Dike of red granite in green hornblendite ; Pigeon island, near Marquette, Mich.

Photograplied and Presented by G. P. Merrill, of the United States National Museum,

Washington, I>. ( '.

Sizes, 4 x 5 and 8 x 10 inches.

301. Slate, showing cleavage and faulting (compare 298) : Bangor, Pa.

.">():.'. Gneiss, showing foliation natural size) ; from blocks in the building-stone
collections of the United States National .Museum; Lawrence and West
A ndover, Mass.

303. Pyroxenite nodules, partially altered into serpentine ; Montville, N. J. (3 nodules

on one plate, published in Proc. U. S. Nat. Museum, vol. xi, 1888, p. 11-. pi.

x x x i i .

304. Quarry in Triassic sandstone; Portland, Conn. The view shows the varying

thicknesses of the beds and their nearly horizontal arrangement.

305. Fold in slate quarry; Bangor, Northampton co., Pa. The slaty cleavage ex-

tends from the left slightly downward to the right and directly across the
apex of the fold.

306. The franklin slate quarry; Slatington, Lehigh co., Pa. The view shows the

slaty cleavage cutting across the bedding at a high angle, the quarry opening
being near the apex of a fold.

307. Slate quarry; Bangor, Pa. In the distant right, at the fool of the derrick, a

fold in the slate is shown s.miewhat indistinctly.

308. Marble quarry ; West hut land, N't. View looking do^ nward from the surface

and showing the inclined position of the beds. (This view forms plate i of
the Handbook of the Collection of Building and Ornamental Stones in the
dnited States National Museum, Smithsonian Report, l885-'86, part Li;.

309. Granite quarry ; Hallowell, Maine. This view shows the lenticular character

of the sheets and their imbricated arrangement. Nearly vertical joint-faces
are shown at the right This viev forms plate viii in the 1 [andbook named

aho\ e.

472 PROCEEDINGS OF COLUMBUS MEETING.

Photographed and 'Presented by Professor P. II. Mell, Auburn, Ala.
Views of the Tallulah falls region of Rabun CO., Ga. Size, ±i x 1\ inches.

310. Lodore fall.

311. Rapids in Grand chasm.

312. Rapids at head of Hurricane fall.

313. ( 'airis head.

:;14. Hickorynut mountain.

315. Glenella spring.

316. Group of Indians.

317. Sweet Sixteen falls.

318. Sinking mountain.

Photographed and Presented by Professor II. L. Fairchild, Rochester, .V. )".
Views of the vicinity of Rochester, X. Y. Size. 6^ x 8^ inches.

319. Pentamerus, or lower Clinton limestone, with tin- Clinton iron ore; ravine of

the Genesee.

320. Another view of subject of 319.

321. Niagara formation ; lower falls of the Genesee ami the Seneca park bridge ;

near view.

322. The same; distant view.

323. Section of a glacial drift hill (kame) ; Cobb's hill. Monroe ave.
3"24. Another section of the kame: same subject as 323.

325. Another section of the kame: same subject as :V2'.\.

Photographed and Presented by (lie Geological Survey of Texas; E. T. Dumble, Stab

< ;, ologist, A ustin, Texas.

Size, 6 x 8 inches.

326. Kountz series: Contact of volcanic ash and chalk.

327. " " Flints on hill.

328. Pilot Knob series: View under bluff of great anticline ; decomposition of tuff

and stalagmites.

329. Pilot Knob series: Bored limestone above tufa.

330. Mount Bonnell series : Under the cliff.

331. " " " Colorado river from western side of mount Bonnell.
:W2. Blue Bluff series: Characteristic Ponderosa marl section.

333. " " - " - •' (continuation of 332).

334. McDonald Quarry series: Flagstone beds.

335. Bee Spring series : Fault in limestone.

336. Barton (reek series: Fault in lime-tone.

337. Travis Peak series: Trinity beds.

338. ' - " Rain erosion.

339. " " " Characteristic topography.

340. " " ■" Trinity and Fredericksburg topography.

341. Sandy Gap: Cambrian cliffs.

REPORT OF COMMITTEE ON PHOTOGRAPHS. 473

342. Shoal Creek shell bunk: Exogyra arietina, Roem.

343. Cataracts; Honey creek, Llano co.

:!44. Walsh's quarry near Austin: Limestone and flint.
345. Flint nodules in chalk ; southern bank of Colorado river.
:i4ii. Lower Cambrian conglomerate ; Burnet co.

:!47. Colorado valley with " Niggerhead " in distance: from Hoover valley, Bur-
net co.

348. "Niggerhead" mountain, Burnet co.

349. Deep Eddy; bank of Colorado river between Bee spring and Fisherman's hut,

near Austin.
:;.">(). Potsdam and Silurian contact: Morgan creek, Burnet co.

Photographed and Presented (in an allium) by Robert Hay, I'. 0. Box 562, Junction

City, Kansas.

Size, Kodak circular, 3| inches diameter.

351. Bear Butte: South Dakota. Prom the south.

352. " " " " Needle rocks, on eastern end.

;;.">:;. " " " " From southwest, showing rhyolite and Dakota

sandstone.
354-360. Sandstone dikes in White river Bad-lands; near Chadron, northwestern

Nebraska. 354, 355, :;:>s and 360 show dike no. 1 ; 356, 357 and 359 show dike

no. 2.

361. .Moraine bowlders showing through the snow ; south of Edgarton, S. D.

362. Drift bowlders in James river bluff; near Jamestown, X. I).

363. ( rlacial bowlder gravel or glacial clay ; Jamestown, X. D.
.'!(i4. Alkaline lake and mud Hat; Coteau du Missouri, X. D.
365. hake in the Coteau ; X. D.

:'.(i(i. Alkaline lake with bowlder beach in the Coteau du Missouri : Northern
Pacific ry., X. I).

367. hake in the Coteau; near Crystal springs, N. D.

368. hakes iu the Coteau du Missouri ; X. D.

369. The Coteau du Missouri; southeast of Crystal springs, N. P. ry., N. D.
370. south

371. " •' '• " southwesl

.i-., .. .. tl u i. a

• »— 1 .. 11 It £1 (1

375. Sumuiil of l lie ( 'oteau ; N. D.

:;7(i. Outcrop of Tertiary grit ; Scotl co., Kas.

."■77. Rainbow falls of the Missouri ; Montana.

378. Yellow chalk surmounted by Tertiary grit ; Norton, Kas.

379-385. Seven views of the " Cresl of the Apishapa," a trap dike on the plains
between Trinidad and Pueblo, Col. The dike rises 500 feetabovethe level
of Ipishapa creek. It.- northern front i< in part.- L50 feel vertically. 379 i>
a view from the west. 380 from the southeast, and 381 from the top looking
eastward; 382 shows the top, 383 is a view from the top, and 384 is a near
view of the southern side, 385 being also a view from the south.

474 PROCEEDINGS OF COLUMBUS MEETING.

Presented by Dr. W. 11. Hobbs, Stab I diversity, Madison, Wis.

Size, 4.! x 7; inches.

386. Warner mountain; from Great Barrington, Mass. Searles quarry on the left.

387. ( 'intact of< 'ambrian 'Silurian) gneiss overlying dolomite : above Searles quarry,

Great Barrington, Mass. Looking southwest : mount Washington in the dis-
tance. The exposures on the left are gneiss, those on the right, either side
of derrick, are dolomite. The exposure where crumpled banding in gneiss
is best exhibited is seen in the left middle ground.

388. Crumpled banding in gneiss ; near Searles quarry, north of most northerly

opening.

389. Polished slab of calcareous muscovite-biotite gneiss ; from above the Hopkins-

Searles dolomite quarry at Great Harrington. Mass. The size of the face is
about 1x2 feet. A well developed cleavage foliation runs parallel to the
side on which the block rests. A nearly straight secondary banding follows
this direction. This banding is completely replaced by a crumpled trans-
verse banding showing the present position of the original stratification
plane. The course of the crumpled quartz lenses can be followed parallel to
that of the crumpled banding (published as plate 14 of this volume).

390. < marry in Cambrian gneiss: above Searles quarry. Great Barrington, Mass.

Shows perfect foliation and straight lamination, dipping toward the right,
and in the lower right-hand corner the straight lamination is replaced by a
crumpled banding which is parallel to the two scries of quartz lenses and
dips westward 40°-60°, conformably with overlying dolomite 100 feet west-
ward. The polished specimen (no. 389) was separated from this exposure in
the lower right-hand corner of the view at .1.

391. Polished specimen of gneiss ; from near Searles quarry, Great Barrington,

Mass. Showing crumpled quartz lenses across lamination and foliation.
One-half natural size.

Photographed and Presented by S. R. Stoddard, Photographer, Glens Falls, X. Y.

Nos. 392 to 414, size 7x9 inches, price post-paid I 50 cents each ; nos. 414 to 4-34,
size 5x8 inches, price post-paid) 30 cents each. (Mr. Stoddard's numbers are
given in parentheses for the convenience of those who may wish to order views, i

392 (66). Clear lake : from mount Jo, Adirondacks. The forest cover of our north-

ern mountains is beautifully illustrated in this view. The next photograph
1393) illustrates the devastation produced by forest-clearing (W. M. D.).

393 (494). The trail of the charcoal-burner ; Adirondacks.

394(486). Lower Ausable lake: Adirondacks. An excellent illustration of a pre-
glacial valley obstructed by a drift barrier and thus forming a linear lake
W. M. D.).

395 (489). Upper Ausable lake: Haystack mountain; from inlet.

396(488). ■' " - "The Gothics;" from inlet.

397 (13). Ausable chasm: Column rocks; a post-glacial gorge cut in Potsdam sand-
stone. This is a good type of the many •j.f.r^r?. of New York, all of which
may be classed as the product of streams turned across old rocky slopes by
drift barriers which now occupy the former valleys (W. M. D.).

:!!)<S. Ausable chasm : Rainbow fall.-.

399(19). " " Grand flume ; from rapids down.

ton (17,. •• •• View upward from Table rock.

401 (492). The White mountains and the Ammonoosuc river.

402 (131). West Point; looking northward from the plain.

403 (60). Charcoal kilns on the Chateaugay railroad.

REPORT OF COMMITTEE OX PHOTOGRAPHS. I 7- >

404 (543). Glens Falls, Hudson river. The great volume of the Hudson river below
Albany is not due to a rainfall supply gathered from a large basin, but to the
drowning of the river by a slight depression of its valley below sea level.
The view at ( dens Falls shows the river in its proper dimensions. It lias
here cut down through a drift cover by which it has been diverted from its
ancient pre-glacial course, and at < dens Falls has been locally superimposed
on a series of horizontal strata, in which it has cut a rocky gorge ami at the
head of which it descends in picturesque falls | YV. M. D.).

40.") (804). Lake George : Panorama from Pearl point to Black mountain.

406. Lower falls : Falls creek gorge ; Ithaca, N. Y.

407 (79). Lake Placid and Mirror lake; from Grand View house.

408(436). Indian pass; Adirondacks.

409 (574). Western panorama from hotel Champlain; Lion mountain.

410 (550). Lake Champlain : Looking northeastward from Westport.

411 (560). The palisades of lake Champlain.
412(550). Barn rock ; lake Champlain.

413 (521). Howes cave, X. Y.; "Alabaster hall."
414(515). " " " "The Eagle's wing."

415(48). Keene valley, N. Y. ; Adirondacks. Characteristic view of lowland of
glacial gravels with which the bottoms of our northern valleys are often so
deeply clogged (W. M. D.).

416 (20). Keene valley, N. Y. ; looking southward from Brook Knoll lodge.

417 (43). " " " Tahawus house.

41S (2.°,). - '• " Beede house.

410(75). Ray brook; Adirondacks. A typical meandering stream in a marshv
flood-plain (W. M. D.).

420 (707). Blue Mountain lake ; Adirondacks. Very expressive view of the smaller

Adirondack lakes, whose origin is to be ascribed chiefly to obstruction by drift
of broad pre-glacial valleys in a rugged, rocky country (W. M. D.).

421 (715). Blue Mountain lake; from Merwins.

422 (404). Ausable chasm ; Adirondacks. A post-glacial gorge cut in Potsdam sand-

stone. This is a good type of the many gorges of New York, all of which
may be classed as the product of streams turned across old rocky divides by
drift harriers now occupying their former valleys (W. M. !>.).
423(34). Upper Ausable lake ; from Boreas bay.

424 (72). View from St. Regis mountain; Adirondacks. A good bird's-eye view of

the lacustrine topography of a rocky drift -covered region.

425 (559). Bog river falls ; Adirondacks. These falls, like all those of our northern

states, result from the displacement of streams from their pre-glacial valleys
by drift obstructions which turned them over old rocky divides. This view
is taken where Bog river enters Tupper lake. The next view (426) shows

the quiel Upper course of the same stream where it Hows over a drift surface
in it yet trenched on account of the rock harrier at the falls \\\ M. I >.

426. Bog river ; near Tupper lake.

427 (5(il i. Whiteface mountain summit.

428 (1096). Stony creek : near Spectacle ponds. Typical form of meandering stream

in floodplaiu anion-' the mountains.

129(1057). Trap dike; Avalanche lake. Massive mountains of foliated gneiss*,
intersected by a dike that has weathered out, leaving a chasm I W. M. I». .

130(1055). Avalanche lake; Adirondacks. A pre-glacial rock-walled vallev ob-
structed by glacial drift (W. M. D.).

431 (1204). Woods Moll, Mass, A low rocky and drift-covered headland between
Buzzards hay and Vineyard sound. The terminal moraine has strong develop
ment in this neighborhood. The tidal currents between the islands hen
abouts are very strong i W. M I >.

1:7.6 PROCEEDINGS OK COLUMBUS MEETING.

4:12(1207). Monomoy point ; looking northward from Monomoy lighthouse, cape
Cod, Mass. Monomoy is a long sand-bar formed by the conflict of wind and
tidal currents south of the elbow of cape Cod. It.- surface is at present
covered by shifting sand-dunes with very sparse vegetation (W. M. D.).

433 (120!i). The Powder hole: Monomoy lighthouse; from the lighthouse.

434(1244). Mount Desert island; from Green mountain. Mount Desert contains
the highest land on the Atlantic coast of the United States. Its east and
west mountain range marks the location of a great granite intrusion in ancient
crystalline and Paleozoic i ?) rocks ; the present height of the range above the
adjacent surface being due to the superior resistance of its rocks to denuda-
tion and not to upheaval. The range is now deeply dissected by transverse
valleys, and these are deepened by glacial action. The fjord-like quality of
the coast and the outlying islands indicate a submergence of the region since
the valley system attained its present form (W. M. 1).).

435 (1246). Mount Desert island ; looking southwestward from Green mountain.

4:;ii. Eagle lake, Mount Desert island ; looking northwestward. Eagle lake lies in
one of the transverse valleys by which the granitic range of mount Desert is
deeply dissected. In the distance the narrow arm of the sea by which the
island is separated from the mainland may lie seen (W. M. D.). '

4.">7 (1241). Mount Desert island : Bar Harbor; looking southwestward from Green
mountain.

4M8 (1245). Mount Desert island : Bar Harbor; looking south westward from Green
mountain.

439 (1228). Mount Desert island: Bass Harbor lighthouse.

440 (1375). Entrance to harbor of Saint John, X. B. ; looking inland. This harbor

is entered through a narrow gateway of rock in which the tidal currents or
"falls "are very rapid. This view shows the "falls" at ebb tide (W. M. D.).

441 (13741. Locality same as 440 ; " falls " at flood tide.

442(1308). Low tide in the basin of Minas ; Nova Scotia. Excellent illustrations
of mud Hats and tide-water gullies on the slopes (W. M. D.i.

443 (1399). Low tide in the basin of Minas; X. S.

444(1311). Hudson river; looking northward from West Point. The crystalline
Highlands of the Hudson are cut across by a deep and narrow gorge, by
which the open upper valley of the Hudson is drained. The whole region
once stood lower, and was then worn down to a lowland of denudation
whose remnants are now seen in the relatively even sky-line of the High-
lands. The denudation of this lowland was completed in tin1 later part of
Cretaceous time. Somewhere in Tertiary time an elevation raised the low-
land to about its present altitude, the uplift being greater in the north than
in the south. In this slanting upland the Hudson cut down its valley, and
the valley widened by the wasting of its sides. The depth of the valley is
dependent simply upon the height to which the old surface was uplifted;
the breadth of the valley depends upon the hardness of the rocks in which
it was sunk. North of the Highlands the rocks are relatively weak ; there
the valley is wide. The Highlands are of hard rocks, and there the valley
is narrow. The great volume of the present Hudson river is due to a slight

depression of the land, whereby sea water is allowed to li 1 the valley for

150 miles from its mouth, as far as Albany. The Hudson proper above
Albany is comparatively a small stream (W. M. D.).

445(1315). Hudson river; looking southward past Poughkeepsie. Since the gen-
eral elevation by which the Hudson cut its gorge through the Highlands
and opened its wide valley from Newberg to Albany and beyond, there has
been a later elevation of a less amount by which the valley-lowland above
Newberg has been trenched by the river to a depth of 200 or 300 feet. Since
then a slight depression has flooded the river with sea water, thus giving it
a volume unduly great for its moderate drainage area. This view shows the
Highlands in the distance. The valley-lowland of Tertiary denudation forms
the sky-line of the foreground and middle distance. The trench cut into
this lowland makes the center of the view, and in this trench the sea water
is now admitted by the depression of the country (W. M. D.).

REPORT OF COMMITTEE ON PHOTOGRAPHS. 477

440 (1307). Hudson river; looking northward from fort Putnam.

447. Palisades of the Hudson ; looking northward from Englewood cliffs. The
Palisades represent the outcropping edge of an intrusive columnar sheet of
Triassic lava. Their present comparatively even crest-line is a remnant of
part of the lowland to which all this part of the country was reduced late in
Cretaceous time. The valley of the Hudson (hei*e seen to the right and the
lowlands of northern New Jersey (not here shown) west of the ridge result
from Tertiary denudation since the uplift of the old Cretaceous lowland
(W. M. D.).

448 (1308). Hudson river; looking southward from fort Putnam.

449(1303). " " West Point ; from fort Putnam.

450(1326). " " " " steamboat "New York."

451 (1019). Chateaugay; from Chasm house.

452. Raquette lake ; mouth of Marion river.

453 (737). Marion river ; Bassett's camp.

454 (1378). Imbricating beach pebbles : at low tide in the hay of Fundy. 20 miles

cast of Saint Johns, N. B.

Photographed and Presented by Frederick //. Chapin, of Hartford, Conn.

Size, 5x8 inches. Published in pari as illustrations of " Mountaineering in Col-
orado," 1890. (Mr. Chapin's photograph numbers are given in parentheses.)

455(267). Pikes peak, Col.; looking northwestward from timber line on Bald
mountain.

45IJ (25). Longs peak, Col. ; Looking north-by-west from Table mountain.

457 (13). " " " view from Key-hole, looking westward.

458 (19). " " " " " summit, looking westward.

459 (36). " " " lateral moraine.

160(15). " " " view from Trough, looking northwestward. Fissured

granite in right foreground.
Oil (14). Longs peak, Col. : view from Trough, looking westward.
462(50). " " " Lake (11,000) and Lily mountain, looking eastward.
Pi3 (350). Uncompahgre peak, Col. ; from the west on the divide.
464(361). In the San Juan mountains; looking southwest-by-west toward bono

cone from (lie summit of Uncompahgre.
405 (345). View from the summit of Uncompahgre ; looking westward.
4<;o (3,44). " " " " " " '• west-by-north.

467(352 . Arete of mount Snaefel; San Juan mountains, Col.
408 (210). Vpsilon peak ; from Deer mountain, F.stes park, looking westward.
ici (214). " '• Front range, Estes park.
t7<> 183). F.stes park. ( 'ill. ; view looking northwestward.
471 (62). " and Deer mountain, Col. ; view looking westward.

172(90). - " " " " " - •' eastward.

173 (438). Acowitz canyon, Col. ; looking southwest.
474 (317). < 'hevenne canyon.

175 105). Alamo ranch and tin- Mesa Verde ; Poinl 1 ■ >■ > U ■ >i 1 1 . near Mancos, Col.

176 i I !'_' i. I 'te I in bans near entrance to Mancos canyon.

177 117). The Cliff-palace, Cliff canyon; Mesa Verde, Col.

178(456). " '• - -

179 ( 17:: . Crenelated fortress; Navajo canyon, Col.

I. XV — I '. r ■ i i. i <... . \m.. \ ..i . :. 1891.

478 PROCEEDINGS OF COLUMBUS MEETING.

Photographed and Presented by Professor Harry Fielding Reid, Case School of Applied

Scii net , ( 'It vi land, Ohio.

X,,>. 480 to 498, size 6x8 inches; nos. 499 to 553, size •'!'. x 4|, Kodak views.
Professor Reid's numbers are given in parentheses. (Some of these views are pub-
lished in Professor Reid's paper, " Studies of Muir Glacier," in the National Geo-
graphic Magazine, vol. iv, 1892, pp. L9-84, pis. 1-16.)

180 207). Ice front of Muir glacier and delta of western subglacial stream.

481 (225) End of Muir glacier ; from camp Muir, 1890.

482 (201). Mounts Case and Wright and Muir glacier; from C7.

483 (200). " " " " " " " " "

484 (205). Ice front of Muir glacier ; from near AB.
185 (206). " " " " " camp Muir.

486 (204). Mounts Case and Wright : from near .IB.

487 '214). White glacier; mount Case on right. An excellent general view of a

-lacier.

488 (203). Mount Wright; from shoulder of mount Case.

489 (216). Mount Young.

490 (221). Buried forest; looking eastward, mount Case in the distance.
491(220). " " " westward.

401' (213 . Moraine near end of Muir glacier.

493 217). Limestone mountain and stranded iceberg; about L0 miles south of Muir

glacier bay.

494 (208). Part of ice front of Muir glacier and stranded ice; from just under M.

495 (209). Winn- of Muir glacier overriding roughly stratified deposits; on western

shore of Muir inlet (published by H. P. Cashing in the American <leolo2ist.
vol. viii, 1891, p. 207.

496 (210). A stranded iceberg: a nearer view than 405.
407 (212). Pinnacles at the end of Muir glacier.

498 (211). " " " " " "

499 (58). Diorite peaks; from Snow dome. C2 is highest peak.

500 (119 . Berg lake ; from Tree mountain.

5i)i (118). Girdled glacier ; from Tree mountain.

502 (36). Main valley; from Tree mountain.

503 (47). Looking down main valley from /'. Tree mountain on extreme right.

mount Young on extreme left.

504 (56). Looking down main valley from top of Snow dome. As in middle and

mount Young on left.

505 8 . Lock basin on top of Nunatak H ; Muir glacier. The white surface to the

left of the lake is rock in strong sunlight.

506 (61). First northern tributary; from Snow dome.

507 (45 i. View from P; White glacier on right, southeastern tributary on left.

508 (67). First northern tributary; from 5.

509 (38). View from Tree mountain; mount Young on right, main lake below it.

510 (103). Origin of western subglacial stream ; Ridge at end of glacier.

511 (55). Looking up the southeastern tributary ; from top of Snow dome.

512 (23). View from north ; Snow dome in the middle. < '., in distance.

513 (40). View from /'.looking up southeastern tributary; Tree mountain on ex-

treme left.

REPORT OF COMMITTEE ON PHOTOGRAPHS. 479

514 (12). Mount Case; from E. across Dirt glacier.

515 (22). View from north, showing mouths of Girdled glacier and < rranite canyon.

516 (24). View from north, looking up first northern tributary.

517 (74). First northern tributary; from."). Snow dome on right; Nunatak / on

left in foreground.
•ils (90). Looking across Dirt glacier from 5 ; A'T in distance over saddle.
519 (87). Mount Wright ; from 5.
•320 (132). Upper part of Dirt glacier; from near 5.

521 (35). Southeastern tributary ; from top of Tree mountain (o).

522 ( 37 ). Looking down main valley ; from top of Tree mountain (o). Aa in middle

part of mount Young on left.

523(33). Range of mountains separating White glacier from the southeastern
tributary ; taken from top of Tree mountain [o .

524 (41). Mount Young; from top of Tree mountain.

525(72). Pyramid peak and Dying glacier : from 5. The distant mountains are on
further side of < rlacier hay.

526(71). Western tributary ; from V. /.', ridge in middle.

527 (20). View from N: White glacier and Nunatak / on right ; Nunatak II in
middle; mount Young behind Tree mountain on left; .ls in the distance in
middle of picture.

528(69). Looking up main ice stream of Muir glacier: from I'. f.z in middle dis-
tance.

529 (120). Berg lake; from lower down on Tree mountain, 1890.

530(75). Nunatak H and moraines around it . ; from V.

531 (68). View from V; second northern tributary is behind mountains on the
right; Black mountain on left ; Nunatak ffin foreground.

532(73). Moraines: Granite canyon ; from V. C, is just over Granite canyon ; Gir-
dled glacier partly seen on right.

533 (49). Girdled glacier and Granite canyon ; from P. ( '., on left.

534 (21 ). View from north ; mount Young in the distance.

535 (40). Girdled glacier and Granite canyon ; from Tree mountain.

536 (is). Upper part of Glacier bay; from end of Headland island, 1890.
537(16). " " " " " near Muir inlet, PS'. in.

538 (94). Delta of the eastern subglacial stream at low tide ; from camp Muir, L890.

539 (5). Part of ice front of Muir glacier, 1890.

540 (7). Pinnacles of ice at end of Muir glacier, 1890.

541 (30). Ice front of Muir glacier ; from the west. Mount Case in the background ■
542. " " " " from (', Sept. 7, 1890.

543(85). " " " - " " " i nearer view i.

544 (!).'!). Station II (under cross I ; seen from camp Muir.

545 (104). Morainal ridge.

5 Hi ( 130). Big rock on moraine.

547 (133). Cone of roundei I stones; just south of C, on Muir glacier (see 550

548 (128). Moraine coming out of Main valley ; view looking into Main valley.
5 Hi i l:;i ). Big rock on moraine.

550 (134). Another view of cone of rounded -tones (see 547).

551(70). Northwestern tributary; from I'. <'- in fore-round on right; Cable

mountain in distance in middle.
552(10). Some moraines on Muir glacier. Nunatak f and snow dome seen from /•.'.
553(26) View from north Black mountain.

480 PROCEEDINGS OK COLUMBUS MEETING.

Presented by tht United States Geological Survey ; •/. W. Powell, Director.

The 51 views numbered 554 to 604, inclusive, are 6 x 8 inches.

Photographed by I. C. Russell, 1891.

554. .Mount St. Klias: from western end of Samovar hills. Agassiz glacier in the

foreground.

555. Southern face of mount St. Klias.

556. Ice cascade in Agassiz glacier, partially covered by new snow.

557. Cascade in the neve of Newton glacier.

558. " " " " of a tributary of Agassiz glacier.

559. Canyon in the Chaix hills, stratified moraine material containing recent sea

shells.

5(30. View from the summit of Chaix hills; looking eastward over Malaspina
glacier.

561. Mount St. Klias; from .Malaspina "lacier south of Chaix hills. Southern
* escarpment of Chaix hills in middle distance.

5t)i\ Marginal drainage , southern base of Chaix hills, looking westward. Moraine-
covered border of Malaspina glacier on the left and scarp of gravel terrace
on right.

563. Abandoned lake beds; south side of Chaix hills. The lake is retained by

Malaspina glacier.

564. Yahtse river; from above ice tunnel, looking southward.

565. " " issuing from a tunnel in Malaspina glacier. The Mull's are of
dirt-covered ice.

566. Moraine-covered surface of Malaspina glacier; near point Manby.

567. Surface of central portion of Malaspina glacier.

568. Alluvial fan now being formed by esker streams: western side of Vakutat

hay.

569. View from southern margin of Malaspina glacier; showing country recently

abandoned by ice.

570. Sitkagi bluffs: Southern margin of Malaspina glacier. The glacier, heavily

laden with moraine, has been cut away by the sea,

571. Vegetation on Malaspina glacier; 4 miles from its southern border.

572. Surface of alluvial fan of the Yahtse; Bhowing partially buried forest.
57.">. Icebergs stranded at low tide ; shore of Yakutat bay.

574. Tree broken by recent advance of Malaspina glacier; near point Manby.

575. Vegetation about southern border of Malaspina glacier.

576. Southern margin of Malaspina glacier ; showing forest growing on the glacier.

577. Second view- of alluvial fan on esker stream.

57s. Glaciated surface on Haenke island : probably covered by ice less than 150

years ag< >.
570. Dalton glacier; from Haenke island. Disenchantment bav.

Photographed by C. 1>. Walcott, September, 1891.

580. Lace falls; Cedar creek, one mile above Natural bridge, Va.

581. Natural bridge, Virginia: Distant view looking westward.

582. " " " from southeastern side.

583. " "' " " northwestern side, looking through arch.

584. " " - ■' southeastern side.

REPORT OF COMMITTEE ON PHOTOGRAPHS. 481

585. Erosion of slaty banded limestone ; bed of Cedar creek, about one mile below

Natural bridge, V;i.

586. Plicated slaty limestone : same locality as 585.

587. Contorted slaty limestone ; same locality as 585. Massive limestone in fore-

ground.

588. Folds in Cambrian shales; northern bank of Cedai creek, one and a half miles

below Natural bridge, Va.

589. Folds in Cambrian sandstones and shales ; railroad cut about one and a half

miles above Hamilton, Tenn., on Doe river.

590. Compressed anticlinal and fault plane in Nashville sandstone; near western

end of Little river gap, ( 'liilhowee mountain, Tenn.

591. Cliff of Cambrian sandstones; southern side of Doe river gorge, about two

miles above Hampton, Tenn.

592. Cliff of Cambrian sandstone ; northern side of Doe river gorge, about two miles

above Hampton, Tenn.

Photographed by W. PL \\\>ei\, 1891.

593. Lakelet in moraine ; Little Timber creek, Crazy mountains, Mont.

594. Amphitheater at head of Little Timber creek.

595. Lake " " " " " " occupies a rock basin.

596. < 'rags of Laramie conglomerate ; Brackett creek, Montana. Same rock as seen

in 597.

597. Laramie conglomerate : formed of pebbles of volcanic rocks: Brackett creek.

Park co., Mont.

598. Morainal debris; characteristic of mountain moraine of Crazv mountains.

Mont.

Photographed by J. Stanley-Brown, 1891.

599. Seal rookery ; shore of Saint Paul island, Pribylov group, Alaska.

600. Crater lake; 300 feet above sea, Saint Paul island, Pribylov group.

601. Black Muff; Fossil-bearing tuff of Cinder cone, Saint Paul island.

603. Contact of two basalts ; Black bluff, Saint Paul island.

604. fault in calcareous clays and sands ; eastern side of Rio Verde, 8 miles below

camp Verde, Arizona (photographed by Cosmos Mindeleff i.

/'/•( si a/ 1 1 1 I hi i In Geological Survey of Canada ; Dr. A Ifred R. ( '. Selwyn, Director, Ottawa,

< 'm, ailu.

Sizes of photographs : 605 to 630, Q\ x8; 631 to 635, 11 x 14. (Original numbers in

parentheses i.

Photographed by Dr. Geo. M. Dawson.

615 (57, Sept. 16, 1889). Fraser river ; Fountain, British Columbia. Showingdepth
of post-glacial excavation in glacial deposits with which the valley has been

partly tilled.

606 (79, Aug. 27, 1890 . Part of the Interior plateau of British Columbia; looking

southeastward from Porcupine ridge (altitude, 6,030 feel ,
i in7 I 77, Aug. 26, 1890). Glaciated surface of basal 1 ; illustrating action of pari of the

'j real Cordillera n -lacier, flowing southeast ward at a heighl of 5,930 feet above
sea-level.

482 PROCEEDINGS OF COLUMBUS MEETING.

608(31,1883). Gorge of Elk river; western flank of Rocky mountains, British

Columbia. Cut through flat-lying lower ( lambrian quartzites.

609 (50, Sept. 23, 1884). Glacier and snow-field at head of Red Deer river; Rocky

mountains, Alberta.

610 (41, Sept. 20, 1S84). Folded Cretaceous rocks I Kootanie formation) ; headwaters

of Cascade river, Rocky mountains, Alberta.

fill (17, June 27, 1883). Bluffs on Pelly river ; Lethbridge, Alberta. Illustrating the
arrangement of the glacial deposits. A. Quartzite shingle, etc ("Saskatche-
wan gravels"); B. Lower bowlder clay; (.'. Interglacial beds, elsewhere
holding peat, and overlain in distant bluffs bv upper bowlder clay (see Re-
port of Progress. 1882-'84, p. 139 C).

Photographed by J. B. Tyrrell.

612 (10, 1887). View northward along one of the upper lake Agassiz beaches ; east

of Duck mountain, Manitoba.

613 (6,1889). Swampy island; lake Winnipeg, Man. Face of cliff showing bowlder

of gray gneiss lying on striated Trenton limestone, overlain by loose blocks
of Trenton limestone ; probably an old beach deposit.

614 (9, 1889). Swampy island; lake Winnipeg, Man. Cliff of Trenton limestone,

overlain by broken but somewhat rounded fragments of same rock ; probably
an old shore-line.

615 (88, 1889). Upper limestone of the Devonian of Manitoba ; Rose island, Swan

lake, Man.

616 (96, 1889). Dakota sandstone, weathered nut into rounded masses near an old

lake Agassi/, shore-line; Kettle hill, Swan lake, Man.

1)17 (103, 1889). Ice-pressed bowlder pavement; southern shore of Red Deer lake.
Saskatchewan.

618 (30, 1890). Cliff of Niagara dolomite; Cedar lake, Saskatchewan.

619 (50, 1890). Trenton limestone; northwestern shore of lake Winnipeg.

620 (57, 1890). Laurentian gneiss; southern shore of Little Playgreen lake, in front

of Norway house. Showing characteristic rounded and lumpy surface.
1)21 (2, 1890). View of cliff on northern side of Deer island, lake AVinnipeg, Mani-
toba. Saint Refer sandstone, capped bv Trenton limestone (photographed
by D. B. Dowling).

Photographed by T. C. Weston.

622(13,1879). Magdalen river and bay ; lower Saint Lawrence. Showing charac-
teristic gravel ridge of estuaries of parts of Gulf of Saint Lawrence and New-
foundland.

623 (9, 1873). Lower Helderberg rocks ; Arisaig, Nova Scotia (see Geological Survey
Report, vol. ii, pp. 37 P and 48 P).

'124(8,1873). Lower Helderberg rocks; Arisaig, Nova Scotia. Showing ripple-
markings.

625 (18, 1873). Lower Carboniferous deposits ; Arisaig coast. NbvaScotia. Showing
thick band of Oolitic limestone.

626(21,1879). Carboniferous rocks; southern shore, Joggins, Nova Scotia. Show-
ing erect Sigillaria (see Acadian Geology).

627(24,1879). Carboniferous rocks; southern shore, Joggins, Nova Scotia (see
Acadian Geology).

628(14,1879). Lower Cambrian rocks (gold bearing); "The < >vens." Lunenburg
co., Nova Scotia.

629 (8, 1889). South Saskatchewan river ; above Battleford crossing, N. W. T. River
valley of the plains excavated in Cretaceous rocks.

REPORT OF COMMITTEE OX PHOTOGRAPHS. 483

630(11,1873). Pre-Cambrian contorted schists: Shipton, Me. (see Greol. Survev
Report, L886, vol. ii. i>. 35 .1 ).

Photographed by R. W. Ells.
631. Twisted gneiss; southern shore of Ottawa river, opposite Montebello.

COO " " li u " " a " "

«••>._> a a a a a a a .. a

634. " " northern " " " " " Papineauville.

6..- a a a a a a a a a

.>■).

The following resolution, presented by Mr. Arthur Winslow, was
adopted unanimously :

Whereas our fellow-member and esteemed colleague Professor Edward Orton is,
through serious illness, unable to be with us : Therefore —

Resolved, That the Secretary be requested to convey to Professor Orton an ex-
pression of our sincere sympathy and of our deep regret that he cannot be present
at this meeting; that we miss his genial presence and deplore the fact that through
his absence we lose much that he might tell us of interest and value concerning
the regions about us, his field of work, in which he has developed so much oi
splendid value to our science.

That we rejoice, however, in being able to congratulate him on his rapid con-
valescence, and that we look forward hopefully to seeing him in our midst at an
early future meeting.

The Chair announced that the Summer Meeting would be held in
Rochester, N. Y., the precise date in August to he announced hereafter
by the Council.

It was also announced that there would lie no evening session of the
Society, but that the Fellows would dine at the Neil house.

The remainder of the morning session and the entire afternoon session
were devoted to the reading of papers. The first paper was entitled :

NOTES o.N THE GEOLOGY OF THE VALLEY OF THE MIDDLE RIO GRANDE.

I'.V E. T. DUMBLE.

The paper was discussed by W .1 McGee, who remarked:

Recenl observations by Mr. R. T. Hill and myself corroborate Mr. Dumble's con-
clusions. We find the peculiar deposit called the Reynosa marl to extend far
beyond the Rio Grande into Mexico with unchanged characters, and to stretch
also far northeastward bul with gradually changing characters until a pari at least
of the series grades into the Lafayette formation of the Mississippi embayment ami
the eastern < tulf and Atlantic slopes. In Mexico and Texas and further northeast-
ward alike, the Reynosa and its homologue, he Lafayette, are the newest forma-
tions of the province excepl the Columbia; and the Columbia is separated from

M PROCEEDINGS OF COLUMBUS MEETING.

the Lafayette-Reynosa by a strong unconformity representing erosion many times,
perhaps many hundred times, greater than that of the post-Columbia period.
Throughout the greater part of the province there is a still mure noteworthy
unconformity below the Lafayette; but this unconformity lias not yet been so
clearly recognized in Texas, where indeed there is reason for believing it to be of
diminished magnitude.

Tliis paper forms pages 219-230 of this volume.
The next communication was entitled :

A REVISION ANh MONOGRAPH OF THE GENUS CHONOPHYLLJJM.

BY \V. II. SHERZER.

Remarks were made by Alpheus Hyatt. The paper is published as
pages 253-282, with plate 8, of this volume.

Announcements were made by the President and Secretary, and the
Society adjourned for the noon recess.

The Society reassembled at 2 o'clock p. m. and listened to a paper
read, in the absence of the author, by W .1 McGee:

RELATIONSHIP OF THE GLACIAL LAKES WARREN, ALGONQUIN, IROQUOIS AND

HUDSON-CHAMPLAIN.

BY WAEREN UPHAM.

| Abstract.

These names, excepting the last, which has not been before used, were proposed
by Professor J. W. Spencer, in 1888, for the must important and distinctly defined
stages of the formerly larger bodies of water that have occupied the basins of the
great Laurentian lakes since the deposition of the drift. Their shore lines, high
above the present lakes, are clearly marked by beach ridges and eroded cliffs.
Large portions of the old beaches and of the enclosed lacustrine tracts have been
mapped by the geological surveys of Ohio and Wisconsin and by Professor Spencer
and Mr. Gilbert, both of whom have recently made important contributions to the
discussion of the history of these lakes, concerning which also I. yell. Chapman.
Fleming, Whittlesey, Newberry, ( Maypole, and others had written earlier. Spencer
holds that these bodies of water were held by harriers of land, so far as they were
true lakes, while he would refer some of the old shove lines to depression of the
land so low as to permit them to be formed by the sea. Mr. Gilbert, on the other
hand, attributes these ancient lakes to the harrier of the ice-sheet during its reces-
sion at the close of the Glacial period, their changes in area and their reduction
from higher to lower levels being due to the gradual uncovering of the land from
the ice by which it had been enveloped, opening thus successively lower outlets.

WARREN UPHAM — RELATIONSHIP OF GLACIAL LAKES. 1:85

With this hitter explanation 1 fully agree, and therefore place the descriptive word
"glacial" before the names of these lakes.

In a paper read a year ago before this Society I presented a general review of the
glacial lakes of Canada, in which the relationship of lakes Warren and Iroquois
and the sea level in the Charnplain epoch was found to imply for the ( !hicago outlet
of lake Warren nearly the same altitude as now, or about 600 feet above the sea.
It was also shown that lake Iroquois, while outflowing at Rome, New York, was at
first probably 100 feet or less above the sea, but that its basin was uplifted, while
its outlet continued at Rome, until the height of this lake was about 300 feet above
the sea. The present paper, which is supplementary to that of last year, after
briefly noticing the three glacial lakes Warren, Algonquin and Iroquois in the
basins of the great Laurentian lakes, is chiefly designed to call attention to the
expansion of lake Iroquois until it became united with the glacial lake winch filled
the valley of the Hudson and the basin of lake Charnplain.

Lake Warren was contemporaneous with the glacial lake Agassiz, which occupied
the basin of the Red river of the North and the district of the present great lakes
of Manitoba, and it may have continued until lake Agassiz began to outflow north-
eastward. It belonged to stages in the departure of the ice-sheet which appear to
have permitted confluent sheets of water to stretch as a single lake from the western
end of the basin of lake < >ntario over the whole or the greater part of the four higher
Laurentian lakes. Its outlet was across the watershed near Chicago, between lake
Michigan and J >es Plaines river, at a height of about 12 feet above this lake and
595 feet above the sea, where now a canal has been cut through on the same level
with the lake.

Lake Algonquin, which was the reduced representative and direct descendant of
the somewhat earlier lake Warren, occupied the basin of Georgian bay and lake
Huron and perhaps portions of the basins of lakes Michigan and Superior. It out-
flowed for some time through Balsam lake and the river Trent to lake Iroquois,
then restricted to the lake Ontario basin. Later it was tributary by the way of
lake Xi pissing and the Matta wan river to the northward expansion of lake Iroquois,
then filling the lower part of the Ottawa basin. The altitude of lake Algonquin
above lake Iroquois in their earlier stages was approximately 200 feet, and in the
later stages of both these lakes it was probably 50 to 150or 200 feet, increasing with
the gradual Uplifting of the country between lake Huron and the Saint Lawrence.

Lake Iroquois began to exist as soon as the recession of the ice-sheet uncovered
the Mohawk valley. The previously existing lake Warren was then drawn down
below the avenue of outflow at Chicago, and became changed, as Mr. Gilbert has
shown, into lakes Algonquin and [roquois, the former either extending from the
basin of lake Huron into those of lakes Michigan and Superior or receiving tribu-
tary rivers from those lakes, and the latter filling the basin of lake Ontario and
receiving the outflow from the former. In mapping the highest shore of lake

Iroquois ill the Ontario basin, Professor Spencer calls this the western portion of
lake Iroquois, and states that this lake spread to the northward and eastward over
the ureal triangular area between the Ottawa and Saint Lawrence rivers, sending

an arm far up the < Mta.wa \ alley.

Bu1 none of the writers on these glacial lakes have studied the question, Where
was the ice-sheet latest a barrier across the Saint Lawrence basin? The directions
of glacial stria' and transportation of drift answer that the ice-sheet in this region

during the closing stage of glaciation was thickest on a hell crossing the Saint

LXVI— Bum.. Soc. \m.. \'<.i . ::. 1801,

480 PROCEEDINGS OF COLUMBUS MEETING.

Lawrence nearly from east-southeasi to west-northwest in the vicinity of Quebec.
Thence its currents pushed up the valley by Montreal, and also down the valley,
filling the broad estuary of the river to the gulf; and on that tract, at or near
Quebec, doubtless the last remnant of the ice-harrier was melted away, allowing
the sea ingress westward to lake ( Ihamplain, to the mouth of lake < hitario, and to
Allumette island in the < Htawa. Previous to this, while an arm of the sea had been
washing the ice-border and thus increasing its speed of retreat in the gulf of Saint
Lawrence and westward to Quebec, the waves of lake Iroquois on the other side of
the narrowing ice-belt in this valley had likewise hastened its departure. Gradu-
ally this lake had extended beyond the basin of lake Ontario to fill at length the
lower part of the Ottawa basin, probably to the mouth of the Mattawan and pos-
sibly at first even crossing the watershed east of lake Nipissing, becoming thus
confluent with lake Algonquin — that is, the Georgian hay and lake Huron of that
time. It had spread eastward around the northern side of the Adirondacks to lake
Champlain and Montreal, and down the Saint Lawrence valley probably almost or
quite to Quebec, when the ice-dam between it and the sea disappeared. The glacial
lake Iroquois, until this time outflowing to the ocean by the Hudson river, then
ceased to exist ; lake Ontario became a separate sheet of fresh water; and the sea.
at a somewhat lower level than lake Iroquois had held, stretched to the Thousand
islands, where the Saint Lawrence river, at first only a few miles long and with
scarcely perceptible fall, discharged the outflow of lake Ontario into the prolonged
gulf of Saint Lawrence.

Another part of this theme remains to be added, telling the history of the con-
tinuous Hudson and lake Champlain valley during the recession of the ice-sheet
up to the time of this opening of its northern portion to the ocean. The absence
of marine fossils in beds overlying the glacial drift on the shores of southern New
England, Long island and New .Jersey, and the water-courses which extend from
the terminal moraine on Long island southward across the adjacent modified drift-
plain and continue beneath the sea level of the Great South bay and other bays
between the shore and its bordering long beaches, prove that this coast stood higher
than now when the ice-sheet of the last glacial epoch extended to its farthest limit.
A measure of this elevation of the seaboard in the vicinity of New York during the
( Ihamplain epoch is supplied, as I believe, by the shallow submarine channel of the
Hudson, which has been traced by the soundings of the United States Coast Sur-
vey from about VI miles off Sandy Hook to a distance of about 90 miles southeast -
ward.* This submerged channel, lying between the present mouth of the Hudson
and the very deep submarine fjord of this river, ranges from 10 to 15 fathoms in
depth, with an average width of 1 1 miles, along its extent of 80 miles, the depth
being measured from the top of its banks, which, with the adjacent sea -bed, are
covered by 15 to 40 fathoms of water, increasing southeastward with the slope of
this margin of the continental plateau.

Luring the whole or a considerable part of the time of the glacial lake Iroquois
this area stretching 100 miles southeastward from New York was probably a land
surface, across which the Hudson flowed with a slight descent to the sea. But north-
ward from the present mouth of the Hudson the land in that epoch stood lower
than now; and the amount of its depression, beginning near the city of New York

*A. Lindenkohl, Am. Jour. Sri.. :;,! series, vol. xxix, 1885, pp. 475-480, an. 1 vol. xli, 1891, pp. 189-
499; -I. I>. Dana, Am. Jour. Sci., 3d series, vol. xl, 1890, pp. 425-437, with map reduced from a chart
of the United States Coast Survey.

WARREN IP1IAM — RELATIONSHIP OF GLACIAL LAKES. 487

and increasing from south to north, us shown by terraces and deltas of the glacial
lake .Hudson-Champlain, which were formed before this lake became merged in
lake Iroquois, was nearly 180 feet at West Point, 27-"> feet at Catskill, and 840 feel
at Albany and Schenectady* Farther northward, according to measurements by
Baron de < reer of the altitudes of the highest shore marks in the part of the Saint
Lawrence basin which was filled by the expanded lake Iroquois, the depression
was approximately 650 feet at St. Albans ; 625 feet on mount Royal at Montreal;
and 700 feet on the hills a few miles north of the city of Ottawa. From these
figures, however, both in the Hudson and Saint Lawrence basins, we must subtract
the amount of descent of the Hudson river, which in its channel outside the pres-
ent harbor of New York may probably have been once 50 or 60 feet in its length of
about 100 miles, as seems to be indicated by the height of terraces on Manhattan
island and in its vicinity. Before the time of disappearance of the ice-barrier at
Quebec this descent may have been diminished, or the seaboard at New York may
have sunk so as to bring the shore-line nearly to its present position; but the
Hudson valley meanwhile had been uplifted, so that an outflow from lake Iroquois
crossed the low divide, now about 150 feet above the sea, between lake Champlain
and the Hudson. This is known by the extension of fossiliferous marine deposits
along the lake Champlain basin nearly to its southern end, while they are wholly
wanting along all the Hudson valley. Indeed, the outflowing river from lake Iro-
quois, or the Hudson during the subsequent post-glacial epoch, channeled the lower
part of this valley to a depth of about 100 feet below the present sea-level, proving
that the land there, as Mr. Merrill points out, stood so much higher than now at
some time after the ice retreated.

When lake Iroquois ceased to outflow at Rome and, after intervening stages of
.outlets existing for a short time at successively lower levels north of the Adiron-
dacks, began to occupy the lake Champlain basin, outflowing thence to the Hudson,
its surface fell by these stages about 250 feet to the glacial lake Hudson-Champlain,
which had doubtless reached northward nearly to the Saint Lawrence. After this
reduction of its level, lake Iroquois had a depth of about 150 feet over the present
mouth of lake Ontario, as shown by a beach traced by Mr. Gilbert, which thence
rises northeastward but declines toward the south and southwest. Its plane, which
is parallel with the higher Iroquois beaches, sinks to the present lake level near
Oswego, New York. Farther southwestward the shore of the glacial lake at this
lower stage has been since submerged by lake Ontario. The Niagara river was then
longer than now, and the lower part of its extent has become covered by the present
lake. From the time of the union of lakes Iroquois and Hudson-Champlain a
strait, at first about 150 feel deep, but later probably diminished on account of the
rise of the land to a depth of only about 50 feet, joined the broad expanse of water
in the Ontario basin with the larger expanse in the Saint Lawrence and Ottawa
valleys and the basin of lake ( 'hamplain. At the subsequent time of ingress of the
sea past Quebec the level of lake Iroquois again fell probably 50 feet or less to the
ocean level. The place of t he glacial lake so far westward as the Thousand islands
was then taken by the sea, with the marine fauna which is preserved in the Ledu
clays and Sn ncava sands.

.1. s. Newberry, Popular Science Monthly, vol. \iii. 1n7*. pp.641 GGO; V. i II. Merrill, Am. Jouin.

s.-i.. :;il series, vol. xli, 1891, pp. IG0-466; W. M. DaA i-. Proi dings "l the Boston Society of Natural

History, vol. xxv, 1891, pp. 318-334; Warren Upham, Hull. G ol -■- Vm., vol. i. 1890, p. 5G6, and vol
2, L891, i'. 265,

188 PROCEEDINGS <>F COLUMBUS MEETING.

In connection with the above the two following papers were read :

THE IROQUOIS SHORE NORTH OF THE ADIRONDACK^.
BY J. \W SPENCER.

In previous papers on the Iroquois shores of the Ontario basin, their position was
definitely located only to a point near Belleville, on the northern side of lake
Ontario. But, from the general character of the country. 1 pointed out the
necessity of extending the Iroquois water across a broad expanse of country to the
highlands north of the Ottawa river, cm the flanks of which shore deposits are
known at various localities. I have also shown that the Iroquois water stood at < li-
near sea-level ; and in my working hypothesis considered the Iroquois water as an
extension of the gulf of Saint Lawrence into the Ontario basin, although more or
less obstructed by ice. Sinee the last paper was written, Mr. O. K. Gilbert and
myself have revisited the region as far as a point 100 miles northeast of Water-
town. ( >wing to Mr. Warren TJpham's recent acceptance of the extension of the
open Iroquois water as far as Quebec, it becomes desirable that the old shore line,
so far as definitely surveyed, should be published.

• After a long stretch of unbroken continuity, the Iroquois beach is abruptly inter-
rupted by rocky cliffs on the side of the escarpment about ■"> miles east of Water-
town. Beyond this point, owing to the broken continuity, the remnants of the
ancient shore are more or less fragmentary. The old subaqueous plain extends up
the broad Black river valley far above Carthage, with gravel deposit- characterizing
portions of its margin. The northeastward elevation of the Iroquois beach in this
region rises at from five to six feet per mile. Beyond Carthage, the country becomes
more broken, being traversed by ridges of crystalline rocks, forming a late exten-
sion of the archipelago of the Thousand islands at a higher level. The drift de-
posits become more sandy, with very little clay, and consequently are less favorable
for the production of well defined beaches. The island character of this region is
particularly unfavorable for the development of well defined shore markings. But
wherever valleys enter the archipelago, their outlets are characterized by delta
deposits or terraces, whose hypsometric position can be predicted in proceeding
eastward.

At Mr. Frank Wilson's, 4 miles east of Watertown, the unquestioned beach is
broken into ridgelets between 730 and 704 feet, with a frontal gravel-bearing ter-
race at 682 feet. Below this horizon there is an extensive terrace plain east of
Watertown at about 535 feet. At the mouth of Indian river, at Natural bridge,
these delta deposits form terraces, with more or less beach structure, at an eleva-
tion between 829 and 802 feet, with a frontal -ravel plain descending from 7S7
feet downward. In both cases, the waves, in carving out the Lower terraces, have
removed portions of the higher ridgelets. Between these limits there is no strongly
marked terrace, hut the lower i- more confined to this regional topography than the
upper; ami where gravelly, the pebbles are subordinate to the sand. For quantity
and size of water-worn pebbles, the gravel deposits at Natural Bridge are physically
the equivalents of those of the Iroquois beach to the southwestward. Above and
below this level, at Natural Bridge, there are no fragments of ancient water lines
liable to be mistaken for the Iroquois level. The elevation of these deposits is that
which would he expected from the measured warping recorded about Watertown.

.1. VV. SPENCER — THE IROQUOIS SHORE. 189

Beyond Natural Bridge there are extended gravel plains, in height conforming to
the terraces at the old mouth of Indian river; but these are often more or less

pitted.

These plains appear to me as due to the presence of floebergs or other masses of
ice stranded upon the old shore. Even if they were shore deposits formed in glacial

lakelets, their elevation is such as to show a common water level. They now face
a lower descending country to the northwestward, and are deformed by the gradual
warping toward the northeast. At I'iteairn, the valley is 200 feetor more in depth,
Conning a deep channel in the late expansion of the Laurentian archipelago. High
on the sides of the valley /.ones of howiders, which are so often characteristic of
old shore lines, are found at heights in keeping with the deformed Iroquois beach.
A little north of East Pitcairn, there is a fine display of terraces, with heach
structure. These are partly in front of a now unimportant valley. There are
several ridgelets, the highest being 942 feet; hut the most important is 930 feet
above tide. These ridgelets descend to a terrace or frontal plain 60 feet below. A
short distance beyond, the terraces of Oswegatchee river are seen. .Inst north of
Fine, they close around and connect a rocky island with the eastern side, and form
a soil of harrier beach. This bar lias an elevation of 972 feet. All of the above-
recorded terraces were leveled. The following are of barometric measurement.
The rise in height in these beaches corresponds to the deformation of the Iroquois
heach, increasing from live to six feet or more for miles toward the northeast,
which amount ought perhaps to be slightly modified, owing to imperfect identifi-
cation in the crests of these terraces or the absence of some portions of the highest

ridgelets.

The next ureal valley is that ofGrassy river. At Clifton Forge {Clarksboro), the
.ild mouth of the valley is well defined byabeautiful gravel terrace at 1,055 feet
(hard, with an inferior terrace or ridge at 45 feet below. Lower than this no well
marked -ravel terrace occurs; hut at S50 feet there is an extensive sand plain,
forminga terrace confined to the valley. The terrace in the last valley is nearly
due north of that at fine, and appears to represent a warping of eight feet per mile.
Out probably the barometric measurement is responsible for the apparent increase
in rate of elevation. Still, the northern uplift may probably exceed that to the
northeast.

The chain of observation was continued by Mr. Gilbert and myself to Racket
river. The elevations were not satisfactorily obtained, as the changing weather
greatly affected the barometer, especially above South Colton. At South Coltonj
there is a sandy plain at about '.Mo tbet (bar.), apparently corresponding to the
plain.- below Clifton Forge and Fine. Racket river presents an interesting change
of channel near St ark post office. It.- old course was in a broad valley, now occupied
by ( 'old water creek as far as South Colton ; but after the Pleistocene revolution, it
cut across hard rocks and deserted its old channel. Following up the Coldwater
valley, we reached a broad sandy terrace underlain by gravel. This plain forms
terraces extending northward along the sides of the valley. It- elevation is
1,215 (? bar.; the weather was very threatening). Other deposits were noted at
1,350 feet, which' were probablj older river terraces. Again, on the brow of the
plateau facing Potsdam, there was a plain at 1,160 feel with a bow Ider pavemenl in
front of it. The value of these measurements is so impaired thai they are only
important in identifying continued elevations of the terrace plains near the late
outlet- of the valleys as far eastward as Rackel river. In descending from the la-t

400 PROCEEDINGS OF COLUMBUS MEETING.

plain there was no extensive valley terrace below the level of South Cotton of
magnitude corresponding to those at Watertown or at Clifton Forge. It might be
noted that throughout this high region all of the pebbles are of local origin and
none that could be identified as Canadian. The Paleozoic rocks were absent from
the drift above South Cotton and Parishvilie. Indeed, some of the apparent sand-
stones are cleavable quartzitic gneisses, and require elose observation to prevent
mistake.

Along the whole northern tiank of the Adirondacks, there is a great poverty of
glaciated surfaces. Near Natural Bridge the direction of the striae was south 7oc
west ami south 55° west. < hi the hills farther south the direction was south 20° to
25° east, and near Harrisville south 10° west. Bowlders were of large size. One,
at a school-house three miles southwest of South Cotton, showed at least 6,000 cubic
feet above surface of the ground.

From the recent explorations, allowing for errors in observation and measure-
ment, it appears that shore deposits occur at the mouths of all the valleys which
entered the Laurentian archipelago of the Thousand islands. Throughout a con-
siderable range of altitude, there is only one set of terraces or delta deposits, always
occurring at the mouths of old valleys, with occasional connecting gravel plains or
terraces of beach-like structure, composed of coarse pebbles, in magnitude com-
parable to the physical development of the Iroquois beach farther westward ; the
lower terraces being mainly sandy and confined to the valleys: and the higher, if
known at all. much above the possible altitude of the Iroquois plain. These ter-
races form sets of ridgelets ranging downward from their crests about 50 feet to the
gravelly deposit of their frontal terraces. This holds true alike for the exposures of
the Iroquois beach east of Watertown and for the recorded terraces at the mouths
of the valley. The next great terrace plain below these gravel shores is about
200 feet and mostly sandy, alike near Watertown and along Grassy river and
elsewhere. The differential rise of the Iroquois beach increases toward the north-
east. Southeast of lake < >ntario it is three feet per mile. At Watertown it is five
or, rather, nearly six feet, and eastward the terraces at the mouths of the valleys
rise from six to perhaps eight feet per mile in a constantly increasing ratio, as
would be expected.

Of all this cumulative evidence, there seems but one explanation, namely, that
these shore accumulations at the mouths of the old valley are identical with the
Iroquois beach further westward and formed one water level. The warping of this
region is established, and cannot be discarded in order to have glacial dams at
various elevations, which of itself appears unnecessary and illogical. But ice ob-
structions between these valleys at the same level would not permanently affect
the water level of the whole; for glacial lakes are evanescent, and some of such, if
they existed, would not have been more than narrow tongues, as shown by the
incomplete surveys. 1 do not here accept or deny the occurrence of local glacial
dams; only the identity of these deposits as the equivalent of the Iroquois shore
seems well established for a hundred miles east of Watertown.

Mr. Upham's recently adopted hypothesis-' of the extension of open water as far
as Quebec during the Iroquois history, and the consequent shrinkage of the theoret-

* Mr. Gilbert informs me that Mr. Upham refers to beaches lower than the [roquois as defined
by me in naming thai shore. One is scarcely expected \>< alter a definition. However, it makes
iini little difference which of the Ontario beaches he extends u< Quebec, as all are far above the
Champlain level.

J. W. SPENCER — THE IROQUOIS SHORE. 491

ical glacial dams 400 miles to the northeastward, is in harmony with my views
previously set forth. The details in the present paper only locate the approximate
positions of the old shore as far northeastward as they have been definitely ex-
plored. Where the upward warping ceases or is replaced by a descending move-
ment toward the sea has not been discovered, so that it maybe found that the
Iroquois shore is lower in the region of Quebec than in the Adirondack region* This
idea of a lesser continental uplift in the northeast than farther southwestward has
already been hypothesized in one of my previous papers and subsequently pointed
out by Baron de Geer.

That much drifting ice occurred in the northeastward extension of the [roquois
water is probable on account of its pitted shores, bowlder pavements and broken
features. It may be even possible that this body of water, which was at sea-level
was cut off from open water by local glaciers descending into the lower Saint Law-
rence valley, but these could not be sufficient to hold for ages a body of water 600
miles long and in part over 100 miles wide much above sea level.

In Mr. Upham's paper on lakes Warren, Algonquin and Iroquois he has given
definitions differing from those of my original descriptions. 1 described lake
Warren as extending over the < Mitario basin as well as over the basins of the upper
lakes, for I know of terraces and other shore phenomena belonging to the eleva-
tion. The only systematic work on the Algonquin water was originally done by
myself and recently continued by Mr. Taylor, and I have shown that its level was
about 300 feet above the Iroquois plain. The dismemberment of the Warren water
was first pointed out by myself and, from the evidence, there appear to have been
many outlets — that at ( JhicagO being only one of them and not the outlet of a sep-
arate tdacial lake.

Mi-. Gilbert's interpretation of the phenomena north of the Adirondacks as being
attributable to glacial lakes does not seem to me to be tenable, from the immense
amount of cumulative evidence set forth in this paper; but all the glacial charac-
teristics of the terraces and pitted plains may be easily explained by floating ice.
acting in the Laurentian archipelago upon the Iroquois shore; which would only
be located as above described even upon Mr. Upham's explanation of the closing
of the Ontario basin by a glacial dam at Quebec.

CHANNELS OVEK DIVIDES NOT EVIDENCE PER SE <>F GLACIAL LAKES.

BY .1. W. SPENCER.

The locality of this paper was visited in company with Mr. < I. K. Gilbert, and
the descriptions given are only sufficient to allow a staternenl of ray views, as 1
consider it a very important region.

The valley of Black river, New York, extends nearly 40 miles above Carthage,
forming an embaymenl on the northern Hanks of the Adirondack massif. Boon-
ville is on the divide between the head of this valley and an eastern branch of the
Mohawk river. The limestone fl 'of the divide is l.lll feet above the sea. From

it the valley rapidly widens, and at a point ten miles to the south it is two miles
in width. At a shorl distance farther southward, the lolls rapidly fall away, leaving

a comparatively low country. A few miles westward, the parallel [roquois beach
records differential elevation of the land amounting to four feet or more per mile.
In the greal valley of the I '-lack river, conspicuous terraces3 occur north of Boonville

402 PROCEEDINGS OF COLUMBUS MEETING.

at 1,190, 1,170 and L, 130 feet. The terraces continue on the southern side of the

divide, and at a point ten miles distant were noted at 1,095, 970, 940, 888 and 830
feel, with the floor of the valley 770 feel above tide. With the differential warping
considered, the identity of the upper terraces is unquestionable. The summit of
the divide is not covered with a gravel deposit ; but a short distance southward
gravel deposits were seen, though their altitude was not measured.

Let us now ask, What harrier retained the volume of water 325 feet above its floor
in a valley one to two miles wide, with the opening country descending in the next
ten miles another .'!2.~> feet? Here we have the action of water in a great open
embayment leaving records at an elevation of 650 feet without any harrier on the
south, unless these waters were retained against the now high level hanks, owing
to a submergence of the region down to sea-level, as it can scarcely he supposed that
a glacial dam could have occurred upon the southern side of a lake. The absence
of the terrace deposits on the divide is easily explained by tin' action of tidal cur-
rents and need not be considered the proof of a glacial river flowing over the water-
shed into a great embayment which could not have retained the volume of water
passing over the divide at hundreds of feet above the bottom of the valley without
an obstruction or submergence to the south. The lower terraces are confined to
the valleys and are not specially considered. Here, then, we And a col connected
with terraces on the northern side, such as are often quoted as proof of glacial
dams, but the terraces on the southern side disprove the efficiency of ice dams to
account for this class of high level terraces.

Professor C. W. Hall was called to the chair, and discussion on the
matter of the three preceding papers occurred, participated in by W J
McGee, G. K. Gilbert, -J. E. Wolff, 1. C. Russell, G. F. Wright and J. W.
Spencer. Mr. Gilbert spoke as follows on Dr. Spencer's papers:

The Iroquois shore-line or group of shoredines has been traced about three-
fourths of the Ontario basin. At the west it lies 100 feet above the modern lake,
and it rises toward the northeast. On the northeastern side it has not been traced
and in that direction there is no land high enough to receive it. As I interpret
the phenomena, the Iroquois water was retained on that side by a glacier occupy-
ing the Saint Lawrence valley, and its surface level was determined by the altitude
of a divide at Koine over which the surplus water found outlet, flowing eastward
down the Mohawk valley. It is Dr. Spencer's view that the Iroquois water stood
at the level of the sea, the land being depressed at that time. Tracing the shore-
line about the southern and eastern sides of the basin, I was aide to map it to the
vicinity of Watertown, where it turns northeastward, lint a few miles beyond I
found the record faint and finally untraceable. At the point where continuous
observation ceased to be practicable the surface of the country is not well suited
to the preservation of a sboi-e record. It consists of a broad plain of sand with
so little admixture of finer material that it is the prey of the wind and is re-
sculptured into dunes. It seemed possible that beach ridges might have been
formed upon this sand plain and afterward obliterated. A detour was accord-
ingly made and the country beyond the sand plain was examined through a
range of altitude including that of the Iroquois beach, in the hope of picking
up it< record once more and following it eastward; but it was not discovered,
although the ground appeared favorable for the reception and preservation of

J. W. SPENCER— THE IROQUOIS SHORE. 493

shore features. It was afterward announced by l>r. Spencer that he had suc-
ceeded in tracing the shore line several miles farther eastward than I had seen it'
and tins announcement stimulated me to renew my search, [n the autumn of
ls'.io I revisited the region in company with Mr. Warren Upham. Starting al
Adams Centre, we ran a line of levels past Watertown to cape Rutland, a point
where the shore features are clearly exhibited at the western margin of the sand
plain. This point, winch had previously been missed by me, was discovered by
Dr. Spencer. The shore-line there has an altitude of 730 feet. Thence we carried
our level line to the eastern margin of the sand plain, where we found a rock sur-
face thinly covered witli drift and well adapted to the preservation of a shore
record. Over this surface we made search through a range of altitudes extending
50 feet below the horizon, where shore features were to be expected, and an
equal distance above. Our results were purely negative. The drift seemed not to
have been disturbed by the waves.

About the same time Dr. Spencer also returned to the held and carried his ob-
servations farther eastward and to higher levels. The results he communicated
to me* accorded so poorly with mine that I proposed a joint excursion, hoping
that if we saw the phenomena together we might come to view them in the same
way. The hope was not realized, but our journey was nevertheless fruitful. It
served to prove that we differ widely as to the criteria by which shore ridges and
shore terraces are distinguished from ridges and terraces of other origin. In
the series of localities to which Dr. Spencer conducted me, from Natural Bridge to
Fine, I saw but a single ridge that seemed to me to simulate a shore ridge, and the
associated phenomena made me confident that that was a case of simulation only,
instead of a shore-line or group of shore-lines 1 saw a magnificent series of kames
and pitted plains, occupying the valleys of a rugged district, and associated with
channels of temporary discharge from one valley to another. The series is too
complex to be analyzed folly during a rapid reconnoissance, but all its elements
announce the margin of an ice field, and none of them announce the margin of a
lake. [ am still of opinion that the Iroquois shore-line ends at cape Rutland, and
that the Iroquois water was bounded on the northeast by a wall of ice on which
the waves could make no permanent record.

A lew words as to Dr. Spencer's second paper: The channel features at the col
have greater extent than he mentioned. The rock floor is swept clear of all drift
except a few bowlders of greal size. North of the col one passes from the rock
floor to the gravel terrace of the Black river valley without notable change of
altitude. South of the col one descends toward the Mohau k for two miles or more
before he finds the rock floor covered by drift or alluvium. The vertical descent in
this distance is not les< than 60 feet. These features appear to accord with the
theory thai a river descended southward from the col far better than with the
theor) that the col was swept clean by tidal currents.

It is true thai there are terraces south of the col accordant in height with the
-real terrace north of it. hut the assumption that these are shore terrace- is gratui-
tous. Terraces originate in many way-, ami it is not always easy to determine the

origin of individual examples. The terrace on which Dr. Spencer bases his argu-
ment was not well displayed nor was it carefully examined. I noted no feature

* Tin--" results nre briefly mentioned ■!-" in tm .To urn. Sei , 3d oeries, vol. \l. I8fl<), pp. 1 1 • 148,

l.\ VI I Bi ii '■n.i Soi \m . Voi„ ::, I--.1

I'.M PROCEEDINGS OF COLUMBUS MEETING.

which can be regarded as diagnostic. Some of the lower terraces south of the
col — those indicated by the anemid asat 970 and 940 feel above tid( — have peculiar
features indicating that they are not Littoral. Though restingon a steep slope, they
are characterized by well rounded bowlders of large size, from one to three feet in
diameter, ruder wave action such material would he rolled down the slope.
Moreover, each of these terraces is margined toward the valley by a parapet of the
same material. The parapet is low, not more than one or two feet bigh, but it
suffices to control the drainage of the terraces. These features suggest that an ice
tongue once occupied the bottom of the valley, and that a torrent coursed between
the ice margin and the valley wall. Our brief visit afforded no time to test this
explanation and I do not offer it with confidence ; but its suggestion will illustrate
to the Society the danger of the assumption that all high lying terraces record levels
of standing water.

Mr. 1. C. Russell remarked :

Recently it has been my fortune to observe in association with Alaskan glaciers
certain terraces with marginal parapets which were formed in the manner suggested
by .Mr. Gilbert, i. e., by streams following the lateral edges of glaciers.

Dr. Spencer replied :

1 have shown in my various papers preceding this that the deformation which
lifted the beaches in the lake region was principally produced after the Iroquois
episode, and that the 350 to 400 feet of eastward elevation between the head of lake
Michigan and the eastern end of lake Erie affected the whole Iroquois plain and
lifted the old shore line at the head of lake Ontario to 86.'! feet above the sea, as
we see it to-day. Hence it seems to me to lie a defiance of observations to regard
the Iroquois shore as having been formed above sea-level, as has been also frequently
stated by Mr.TJpham, although Mr. Upham now extends the Iroquois water to the
vicinity of Quebec.

That the region north of the Adirondacks may have been a sea filled with ice-
bergs or even a glacier is not considered here, but only that the Iroquois water-plain
continued at least 100 miles northeast of Watertown — a theory supported through-
out this very broken region (a former archipelago) by delta and terrace deposits at
the mouth of every river at elevations corresponding to the deformation measured
in the vicinity of Watertown. In composition and physical structure the appear-
ance is close, there being no other deposits liable to misidentification. Throughout
this region there are other than the delta and terrace deposits at the mouths of all
the old valleys corresponding to the Iroquois plain ; hut even though such deposits
may be christened "kames" and "pitted plains" by glacialists, their uniform
glacial origin has not been so demonstrated by actual connection with modern
glaciers that their occurrence is ex cathedra evidence of glacial dams. It is not
doubtfully located deposits upon which I based my criteria, but the recurring delta
and terrace deposits at the river mouths; hence the grounds which make my dis-
tinguished critic and myself " differ radically as to the criteria by winch shore ridges
and shore terraces are distinguished " from glacial levels; nor can 1 gerrymander
glaciers into the region to account for the chains of phenomena which are regarded
as characteristic of the Iroquois water-level ; hut it is unsafe to theoretically throw
glacial dams across beach deposits.

J. \V. SPENCER — THE IROQUOIS SHORE. 195

Mr. Gilbert's suggestion, in connection with the second paper, — that the valley
south of the divide was filled with ice, and that the terrace, 200 feet below the highest)
indicates the coursing of a river between the ice and the side of the valley, eroding
the drift-floor and forming a parapet only one or two feet high, — should be placed
alongside of the explanation of the cleaning out of all the drift from the summit of
the col, where the current must have been more sluggish, by a glacial river. The
object of this paper is only to point out a conspicuous example where terraces do
occur upon the southern sides of the valley divides, in regions of reputed glacia'
lakes, and therefore the absence of the terraces upon the southern sides of divides
must be proved and not simply asserted.

President Gilbert resumed the chair, and the following paper, the illus-
trations of which had been exhibited the preceding evening, was then
read :

THE GEOLOGY « » 1 THE CRAZY MOUNTAINS, MONTANA.

BY .1. E. WOLFF.

Remarks were offered by J. S. Oilier, G. K. Gilbert, B. K. Emerson
and Arthur Winslow.

The paper is printed us pages 445-452 of this volume.

This was followed by —

NOTES ON THE GEOLOGY OF THE YUKON BASIN.

I!V C. WILLARD HAYES.

[Abstract.]

During the summer of 1891 the writer was detailed by the Director of the United
States Geological Survey to accompany Lieutenant Frederick Sebwatka on an
expedition designed to explore the southern portion of the Yukon basin, Alaska.
The route followed was by way of Taku liver, lake Abklen, and Teslin anil Lewes

rivers to the confluence of the Lewes and Pelly, which form the Yukon; thence
s< hi 1 1 1 west ward through the basin of White river, across the interior range of the
Saint LI ias mountains by a pass at the bead of White river, and down Chittenah and
Copper rivers to the coast. The distance traveled was about 1,000 miles, over 700
being through unexplored country. The principal geographic results of t he expe-
dition are t lie approximate mapping of Taku river, lake Ahklen and Teslin river ;
also of a large part of the basin of White river, and portions of the Saint Elias
mountains. Systematic observations on the hard geology were rendered imprac-
ticable by the difficulties attending t ra\ el in the region traversed. The nick.- along
White river basin are chiefly eruptives, with a few highly altered sediments of un-
determined age. The interior range of the >aint Elias mountains extending north-
west ward toward mounl Wrangell has a simple synclinal structure and is composed
chiefly of Carboniferous and Triassic strata. The white volcanic tuff which has
been noted bj various travelers on the Lewes ami Pelly was found t" increase
gradually toward the west, reaching a maximum of from 50 t'> 7"> feel in thickness
in the upper While river valley, from that point decreasing very rapidl} west-
ward. The probable source of the tuff is a high conical peak in the northern

496 PROCEEDINGS OF COLUMBUS MEETING.

border of the Saint Elias mountains and just west of the 141st meridian. Several
glaciers were found flowing northward, but the ice drainage in that direction is
small compared with that southward from the same mountains, and the lower limit
<>f the neve fields is over 4,000 feet higher on the northern than on the southern
side of the range. The northern limit of glaciation in the White river basin is
only about forty miles north of the present termination of existing glaciers, and
the greater part of the basin appears never to have been covered by an ice sheet.

The substance of this paper will be found in the National Geographic
Magazine, volume iv, 1892, pages 117-152, with plates 18-20, under the
title "An Expedition through the Yukon District."

The next communication was entitled :

GEOLOGY OF THE PRIBILOF [SLANDS.
BY JOSEPH STANLEY-BROWN.

On the chart of Bering sea and the Arctic ocean issued by the Hydrographic
Bureau for 1889 are compiled the soundings made in those waters up to that date.
It requires hut a glance at this chart to make plain the fact that Bering sea is in
large part an extremely shallow body of water. An elevation of 300 or 400 feet
would convert most of the present sea bottom into a vast verdure-covered tundra,
whose gently undulating surface would be dotted with lakes and intersected by
sluggish winding streams. Upon such a land surface the four tiny islets to which
this brief sketch refers would appear as conspicuous elevations.

In the waters of this shallow sea in very recent geologic time were created the
Pribilof or Seal islands.* Their formation was a simple process, and it- successive
steps are recorded with unusual legibility.

In offering the results of a study f of this little geologic unit, the facts upon which
conclusions are based will he given only when clearness demands their presentation.

The islands owe their origin to vulcanism. The geologic agents still busily en-
gaged in modifying them are the surf that heats ceaselessly upon their shores; the
ire which surrounds them in winter ; the drifting sands; and the luxuriant wild
grasses and other herbage. Precipitation, though generous, is rarely violent, and
erosion plays an insignificant role.

Saint Paid island, the Largest member of the group, is 12 miles long and from li
to S miles wide. Its surface is diversified by at least a dozen cones and vents of
unusual symmetry, surrounding in irregular fashion a true crater some 600 feet in
height, called Bogoslof. The shores are lowlying, and sea-cliffs of conspicuous
height are infrequent.

After the initial establishment of an outlet for the molton material, free from the
intrusion of the sea, there were four well marked episodes in the career of the
island. From this central point, that probably finally became the present Bogeslof,
there welled out great masses of lava which made their way outward in all direc-

* The Pribilof islands are in latitude J7° north, longitude 170° west from Greenwich, and an- about
201) milt's northwest of (Jnimak pass, one of the natural waterways of tin- Aleutian chain through
which vessels find their way into Bering sea.

f i (pportunity for this st,udy was had in the summer of 1891. while the writer was acting t i-i n t >. •-
rarily as an agent of the Treasury 1 > spartment for the investigation of the condition of seal life on
the islands,

I )

J. STANLEY-BROWN — THE PRIBILOF ISLANDS. 407

tiuns until overcome by the cooling waters of the ocean. This flow of highly
vesicular basalt, rich in Olivine, can be seen at many points on the shore. It forms
the floor of the island, and where not covered by overlying material its tongue-like
prolongations make reefs dangerous to navigation. Upon this basaltic pavement
were built up meanwhile the vents and cones, which now stand as perfect as on
the day of their completion.

The third step in the process of construction was a second discharge of lava from
the central crater^ aided by feebler outpours from the vents which surround it.
This constitutes the overlying sheet. It is readily distinguished macroscopically
from the basement lava ; it is identical with it in mineralogic composition, but it is
more highly crystalline, and structurally it is pumiceous or spongy in texture rather
than vesicular. The contact of the two sheets is clearly marked and is invariably
near the water level. This latter fact is not due to wave action, for the markings
I: flowing lava remain on the basement surface at the line of contact, In this
upbuilding process perfectly arched volcanic tunnels with thin domes were formed
by the molten streams, while over the surface of the flow many jets of lava were
cooled and fractured into natural cairns so like the artificial monuments or " miaks "
made by the natives as to be readily mistaken for them. EUwould be difficult to
liud more trustworthy registers of orographic changes than these tall, tapering
cairns.

The central portion of the island is today just as it was created: The lavas lie
unchanged in form and unaltered in their mineralogic constituents; no general
shifting of level has occurred to disturb the uprightness of the slender miaks, to
break down the fragile domes of the volcanic tunnels, or-to interfere with the hori-
zontally of the basement lava. On the southern shore an old sea beach of rounded
pebbles and bowlders made of fragments of the floor basalt now stands 25 or 30 feet
above the sea level, but the area involved would be represented only by a circle a
quarter of a mile across Thi' disturbance was local and due to the formation of a
small cone, only a few vestiges of which have been left by the sea. No glaciation
has smoothed away the cairns, carved the surfaces of the huge basaltic blocks, or
rounded their jagged edges. The cones and vents, which often bear tiny lakelets
in the cup-shaped depressions on their summits, stand unimpaired in their syin-
metry. In no place has erosion left a scar. No erratics are found on the higher
levels, except such pebblesas were brought by a novel geologic agent — the stomachs
of seals and sea lions.

Every scrap of physical ami petrographic evidence indicates the recency of the

island's formation, and a sea-dissected cone, known as Black bluff, on its eastern
side furnishes additional testimony. Distributed through this cliff of basaltic tuff

arc rounded calcareous clay fragments, bearing fossil shells.* Extinct forms of

it is stated by Elliot! in "Our Arctic Provii " (p 22!)) that in Black bluff occur "stratified

horizontal lines of light-graj calcareous conglomerate or cement, in which are embedded Bundrj
fossils characteristic of and belonging i" tic Tertiai'j age, such as Cardium gra nlandicum, < '. deeo
ruin,. <i.i i tarti pectunculata, etc." It is true thai tin- general appearance of tin' el iff would
indicate tuch i state of affairs, bul when the structural details are closely studied ii is found thai

while ili'' i-lin lii- (i so whal stratified appearance that might have been due to n puddling of the

cinders and ashes of which it is composed, tli" fossils ar mfined i" a clay rock whicl curs in

much on mile I fragments IV a few inches to two feet In diameter. These are scattered with some

irregularitj and not copiouslj through the mass, and are in all stages "t decomposition incideul
to the agencj of heat and moisture, rhe evidence would app conclusive that these fi

ments were caught u] ichanicallj : I nl nd distributed through the

i during its ere il ion,

198 PROCEEDINGS OF COLUMBUS MEETING.

mollusks have been found there, but of the fifteen species brought hack bynie this
past summer and identified by l>r. Win. H. Dall,* all have living representatives
in Bering sea.

When the three constructive episodes were ended, then began a period of de-
struction and rearrangement of material about the margin of the island. Here the
waves converted the lavas ami tuffs into bowlders, pebbles and sand, and distrib-
uted them along the shores in characteristic forms; the ice crowded the coarser
material inland, forming ramparts invulnerable to the assaults of the sea ; over
this in turn the sand was scattered, and not only were the margins thus extended,
but the Lowlying lava tlows were built upon and the newly formed areas firmly
joined to the mainland. The winds caught up the sands and built them into dunes,
which continuously encroach upon the sea and which are made constant by the
long roots of the wild grasses that ever grow upward as more sand is added. To
these processes an due about one-fifth of the area of Saint Paul, and such topo-
graphic features as the lagoon, the ponds along the shores, and the lakes at North-
east point. This work of construction continues and will probably keep pace with
the destruction of the island.

About 36 miles soi^heast of Saint Paul lies Saint George, an island a little smaller
than its companion and very different topographically ; hut few cones dot its sur-
face ; accessible shores are exceptional : and instead of lowlying sea margins, hold
precipitous bluffs from 300 to 900 feet high are the rule — the island stands like a
mesa on a watery plain. While the story of its formation is in the main that of
its neighbor, there is another factor involved, that of orographic movement. There
is a floor of dark vesicular basalt, but the point of the first outpour is not well
defined. From Oolakaiy.i. the name given to the remains of a vent near the middle
of the island and now over 900 feet high, came the hulk of the succeeding flows.
Indeed the extravasation from this center, aided perhaps by outflow from other
vents to the northeastward, built up the entire eastern half of the island. This
main vent also contributed a sheet to the westward, which was augmented by
material from a great cone on the northern shore. This cone has been more than
half eaten away by the sea and now forms High bluff, a perpendicular tuff cliff of
nearly 1.000 feet.

* Dr. Dall's report is as follows:

" Washington, D. <'.. November 13, 1891.
Iicar .All-. Stanley-Brown :

The fossils fr Black Mutt', Saint Paul island, Bering sea, an-, so far as determinable, of recent

species still living in the same region, though other collectors have obtained at the same Ideality

specimens of extinct forms. Beside remains of an ophiuran starfish and the tube of a worm, like

that made by Sabella, there are remains of fifteen species of mollusks below enumerated. The

figures in brackets following the name indicate the number of times the species occurred in the

collection, ami thus their relative abundance.

* Buccinum tenue, Gray ? [3] * Lepton grande, Dall [■!]

* Buccinum polare, Gray '.' [I] Cardium gra niandicum. Gmel. [18]

* A dmete couthouyi, Say ? [1] .' * " islandicum, L. (decoratum, Grew.?) [15]
Natica clausa, B. and S. [4] Tellina (Angulus), -p. [1]

Modiolnria nigra. Gray [In] * Macoma {sabtitlosn, Spgl. ?) [1]

Nucula, s]>._ perhaps V. tenuis [1] Kennerlyia grandis, Dall [1]

Leda. sp. [1] Sax 'cava arctica [11]

* Yoldia limatula, Say [1] * Panopea, sp. '.' fragment, possibly a Saxicava.

The species marked with an "* " have not been re pone. I from t hi- locality before.

Yours very truly,

Wm. II. Dai,l,

Paleontologist, U. S. Geological Survey.'''

J. STANLEY-BROWN — THE PRIBILOF ISLANDS. 490

An uplift then gave to must of the island an additional elevation of 200 or 300
feet, accentuated the ridges formed by the outpours, gave them a monoclinal aspect
by converting their northwesterly fact's into bluffs as steep as they could he made
by great blocks of broken lava, and formed shallow troughs between them and the
shores. The parallelism of the faults is well displayed to any one standing on the
summit of the central vent.

With two exceptions the lavas of the islands are basalts identical with those of
Saint Paul, save in the alteration of their olivine. The decomposition of the olivine
is in all stages of advancement, accompanied by the formation of red oxide of iron.
Otherwise it would be impossible to distinguish these lavas, microscopically, from
the rocks of Saint Paul.

On the northern shore of the island, at a point just east of the village, a basaltic
dike from 2 to 3 feet in thickness and parallel to the ridges, cuts through the tuff,
which here overlies and rests immediately upon the floor lava. This dike, though
a true basalt, differs from the adjacent rock in that it contains enstatite in addition
to the usual augite. Just opposite this dike, at ( rarden cove on the southern shore,
Mr. Elliott* states that he noted a " large dike of bluish or greenish-gray phonolite,
in which numerous small crystals of spinel are found." Unfortunately this dike
could not be discovered by me on my visits to Garden cove, but there is at that
locality a large mass of compact greenish-gray peridotite, which dips northeastward
at about 45°,and upon the upturned edges of which rest, unconformably, the over-
lying lavas. The area of this mass and its relation to the other material cannot he
entirely made out. The peridotite is composed of enstatite and olivine, and ser-
pentinization is well advanced.

At the only two points on the island where the shores are lowlying, the floor of
dark vesicular lava is horizontal and near the level of the water. This may not in
all cases be due to wave action. ( hit lying reefs are rare, and the water surrounding
the island is, as mariners say, " bold." The earlier constructional forms are nearly
obliterated; no true crater remains intact; and hence the cuprshaped depressions
at the summits of the cones and vents of Saint Paul are here lacking. No natural
cairns or volcanic tunnels are to be seen, and the surface lavas along the ridges often
have the form of plates, of all degrees of thinness, that ring like porcelain when
1 rod upon. There are no marks of glaciation or of erosion, and no erratics occur.
Disintegration is apparently the only process now going on.

There remain two other tiny members of the group, Otter and Walrus islands,
each about (i miles oil' the shores of Saint Paul ; but their geologic story is SO similar
to, arid so identified with, that of their greater neighbor that, for the sake of brevity,
its recital is omitted.

There are two fragments of paleontologic evidence connected with the islands
which, as they have been used by writers, demand a cautionary word. The tusk
of a mammoth was found in the sands of Northeast point on Saint Paul island, and
the tooth of one is reported as coming from the shores of Sainl George. As there

is not a foot of earth upon either island, save that which has resulted from the

decomposition of the native rock and the decay of vegetation, the value of puch
tesl imony is questionable.

Small as the I'rihilofs are, they afford ground for differences of opinion. In
writing of these islands, Mr. John Muiri bas said that they "appear in general

\i-i i- Proi i ." p. ■_"J7.

| Arctic ('nil iiK' Revenm Cuttoi C'orwin, 1881 Notes uiul Olmerviil ions," p 1 1".

500 PROCEEDINGS OF COLUMBUS MEETING.

views from the sea as mere storm-beaten remnants of a once continuous land, wasted
into bluffs around their shores by the action of the waves, and all their upper sur-
faces planed down by a heavy oversweeping ice sheel and slightly roughened here
and there with low ridges and hillocks that alternate with shallow valleys. None
of these feature.-, so far as 1 [he] could discover, without opportunity for close ob-
servation, showed any traces of local glaciation or of volcanic action subsequent to
the period of universal glaciation."

It is hardly necessary to state that this view of the islands does not accord with
my brief resume of their origin and career.

Told in a sentence or two. the history of the Pribilof islands is this: In post-
Pliocene time they were formed by successive outflows of basaltic material ; Saint
Paul ami its two tiny companions remain as created, save where destructive and
constructive agencies have been and still are at work on the shore margins ; after
its creation by a similar volcanic process, Saint < reorge was modified by orographic
movement that revealed a portion of the sea floor, and then began the work of
annihilation which has since continued.

The tendency of the evidence gathered is toward a synchronous creation of all
the islands of the group, but no indisputable facts upon which to base a conclusive
argument could he obtained.

The last paper of the day was on —

SOME XEW FOSSIL FISHES FROM THE CLEVELAND SHALE.

BY K. W. CI.AVPol.i: AND W. CLARK.

The fossils were exhibited and discussed.

The following invitation was announced :

The Fellows of the Geological Society of America are invited, on the
part of some of the colleagues of Dr. Orton in the Ohio State University,
to lunch at the Columbus Club to-morrow, Thursday, at 12.30 p. m.

Announcement was again made of the dinner at the Neil House in the
evening, and the Society adjourned for the day.

Session of Thursday, Decembeb 31.

A letter was read from Professor Edward Orton. in reply to the resolu-
tion of Wednesday morning, as follows:

Columbus, Ohio, Bee. 30, 1891.
Professor II. L. Fairchild,

Secretary Geological Society.

Columbus, Ohio.
My Bear Sir:

I am deeply sensible of the kindly feelings of the Geological Society of America

as expressed in the resolutions touching my present disability, which were for-

W J Mcgee — A measure of isostasy. 501

warded to me this day, and I desire you to convey to the Society my grateful
appreciation of its sympathy and good wishes.

I regret more than ! can tell you my inability to add anything whatever to the
pleasure or profit of the Columbus meeting, to which I have been Looking forward
with high expectations for the last six months.

I rejoice with you in every addition that is being made to our knowledge of
American geology. I count it a great honor and privilege to have been able to con-
tribute even in the humblest degree to its advancement, but no one realiz.es more
distinctly than I do at this time how small a part the contributions of even the
most gifted member of our profession make to the wide and ever widening river of
our knowledge. I am sure that we all recognize the fact that our work so far is
mainly limited to the headsprings of the river.

1 close with the sentiment, "The Geological Society of America, esto perpetua."
Very truly yours, Edward Orton.

The first paper read was entitled:

Till-: GULF OF MEXICO AS A MEASURE OF ISOSTASY.
BY W .r MCGEE.

[Abstract.']

The term " isostasy" was coined by Dutton to denote a condition of static equi-
librium in the terrestrial crust, in virtue of which areas of degradation rise and
areas of deposition sink. The earlier data on which the doctrine of isostasy
depends were indirect, i. e., they were inferences from ancient formations and old
surfaces; but it is now found that the modern continental movements affecting
areas of deposition yield direct data sustaining the doctrine. Such data maybe
either quantitative, when the rate of movement is measured, or qualitative, when
movement is ascertained but not measured. The most trustworthy measured ex-
amples are (1) the Netherland coast, which has been under observation for a mil-
ieu i in n and which is subsiding beneath the sediments of the Rhine and its neighbors
at a rate varying from 0.09 to 0.75 meter per century, the mean since L732 being 0.26
meter; and (2) the New Jersey coast, which is subsiding beneath the sediments of
the Hudson and Delaware at the rate of about two feet per century. Scarcely less
decisive evidence of subsidence, though at unmeasured rates, is yielded by every
noteworthy deposition tract of the globe (exclusive of Africa, where the data are
inadequate), including the embouchures of the Amazon, the Yang-tse-kiang,
1 1 wang-ho, la Plata, the European rivers embouching into the black and Azof seas,
t he Volga and I Iral, the Syr I (aria and Amu Daria (together feeding the Aral sea .
the Ganges and Bramaputra, the "Five Rivers" headed by the Indus, the Saint
Lawrence, the Po and its neighbors, and the Mississippi. On reviewing this evi-
dence ii appears that every considerable deposition tract beyond the reach of Pleis-
tocene glaciation, vulcanism and orogeny is subsiding; that, other things equal and
so far as the data are available anil reliable, the rate of subsidence is proportional to
the relative areas of degradation and deposition ; and thai, ot her things equal and
ho far as the data are available and reliable, the subsidence is proportional to the
activity of the rivers in the correlative degradation tracts. So the direct data con-

I..W III Bi'i.i., 9oi . Vm., Vol. 3 1891.

502 PROCEEDINGS 017 COLUMBUS MEETING.

cerning isostasy derived from the geologic record arc supplemented by a trust-
worthy body of direct data derived from the physiography of the earth in its
present condition ; and the direct data arc superior to most of the indirect in that
they arc susceptible of relative, and in some instances positive, evaluation.

The Gulf of Mexico is one of the most fortunately situated deposition tracts of
the globe for the measurement of isostatic subsidence in that it is a nearly closed
land-rimmed basin of considerable area fed by drainage from a many times larger
degradation tract j and, moreover, the sedimentation is not confined to a single
delta, but is distributed in simple and easily ascertained fashion. Now, the Gulf
coast has only recently been surveyed with precision, and the surveys have not
been repeated in such way as to give quantitative rate measurements of movement ;
but the physiographic evidence of subsidence is unmistakable and indicates a mean
rate not less, and probably more, than a foot per century. This rate is somewhat
less than the estimated degradational transfer of material requires. Moreover, the
physiographic indications of subsidence vary in strength about different parts of
the coast; they are weakest in the northeast, where the affluents are short and
feeble ; stronger in the northwest, where the affluents are longer and more potent ;
strongest in the north about the delta of the chief river of the continent. In brief,
if the Gulf of Mexico be considered as a unit, its shores appear to he subsiding
about as rapidly as isostasy demands; and considered as an assemblage of deposi-
tion tracts, the local rates of subsidence appear to be delicately adjusted to the local
rates of deposition. Accordingly, the data yielded by this fortunately situated
deposition tract indicate that throughout the vast ideologic province of southeast-
ern North America isostasy is probably perfect, i. <\, that land and sea bottom are
here in a state of hydrostatic equilibrium so delicately adjusted that any transfer
of load produces a precisely equivalent deformation.

It is well known that the later formations of the Gulf province (notably the
Columbia and Lafayette formations) represent continental oscillations reaching
several hundred feet in amplitude. Now in contrasting these great oscillations
with the gentle modern movement of the coast, they are found to differ widely ;
the modern subsidence is a gentle warping in such direction as to deepen the basin
and gradually submerge its perimeter, while the old oscillations were wide-spread
and involved both sea-bottom and continent; the modern movement is slight and
commensurate with the simple and uniform processes of erosion and sedimentation,
while the old movements were cataclysmic and utterly transcended the influence of
rain and rivers. Accordingly, while the modern movements give abetter measure
than has been obtained elsewhere of the efficiency of degradational transfer of
matter as a cause of deformation, the movements recorded in the Columbia and
Lafayette formations were of so much greater amplitude that they may not be
referred to a similar cause; therefore in this province, as in others, it becomes
necessary to discriminate the two classes of earth movements elsewhere called
respectively antecedent and consequent. So the modern province measures the com-
petence of isostasy, the ancient province its incompetence ; the modern Gulf illus-
trates the magnitude, the ancient Gulf the minitude of isostatic deformation as a
means of continent-making.

Although isostatic action alone is incompetent to explain the great continental
oscillations attending the deposition and degradation of the Columbia and Lafayette
formations, certain peculiarities in these oscillations maybe hypothetic-ally explained
through the doctrine of isostasy. During the low-level periods represented by the

W .1 MCGEE — A MEASURE OP ISOSTASY. 503

deposition of the Columbia and Lafayette formations and during 1 1 it* high-level
periods represented by the degradation of both these format ions, the continent was
warped in curiously consistent fashion ; during both low-level periods there was
an axis of maximum subsidence approximately marked by the cities of Charleston
and Memphis and an axis of minimum subsidence approximately marked by cape
I latteras ; and during both high-level periods the ( !harleston-Memphis axis was one
of maximum uplift, and the Hatteras axis one of minimum uplift — i. e., the former
axis was one of maximum and the latter of minimum movement throughout the
oscillations. Now, this warping is so related to the varying configuration and un-
equal density of the southeastern portion of the continent as to suggest that it was
produced by changes in stresses growing out of the varying degrees of submergence,
[f the hypothesis be established, the efficiency of isostatic action will become so
extended as to demand recognition among the more important, though always
secondary (or consequent), agencies of mountain-building and continent-lifting.*

A spirited discussion followed the reading of the paper, participated
in by G. K. Gilbert, E. W. Claypole, I. C. White and the author. Pro-
lessor White remarked :

My studies of the valleys of certain rivers in the Appalachian region have led to
similar conclusions concerning the susceptibility of the terrestrial crust to changing
loads. Several instances of warping apparently caused by subsidence due to load-
ing have come to my knowledge, the North Susquehanna valley between Pittston
ami Bloomsburg being a conspicuous example.

Mr. ( rilbert said :

The communication is an important contribution to the subject, in that it recog-
nizes the limitations of isostatic action. The phenomena of orogeny and epei-
rogeny are too complex for complete explanation by the single cause of loading and
unloading, which are really conservative processes; and research concerning the
primary causes is facilitated by definition of those of secondary character.

Professor Claypole remarked:

While forced to express admiration for the exhaustive, able and eloquent state-
ment just presented, 1 am impelled also to point out certain objections to the theory
that given areas sink because of loading, while contiguous areas rise because of un-
loading. If the theory were true, the coordinated process would tend to keep rivers
and other geographic features indefinitely in their places, while in reality they are
constantly shifting. It seems to me that under this theory the true order of the
processes is reversed ; that in point of fact areas of deposition become such by
reason of subsidence, and that contiguous areas are degraded because of elevation.
Again, it seems to me that the argument proves too much — that the subsidence of
the Netherland and New Jersey coasts is too great to he produced by the relatively
slight deposition now taking place on the sea bottoms. On the other hand, the
theory fail- to account for the origin of such great features of the earth's surface as
the < lull' of Mexico and the Rocky mountains ; so that some more general forces
would sei-in to he re 1 1 1 li re 1 1 to e\ plain the 1 1 io\eii lent s of continents and sea bottoms.

A theory thai needs to he eked out with another seems si I peril llou s. Moreover.

I lie greater pari of the paper in printed in full in the Am. Journ. Sei., vol xliv, pp. it: 192, 1892,

504 PROCEEDINGS < >F COLUMBUS MEETING.

the argument that the subsidence advances in proportion to the load imposed is
untenable, because, whatever the amount of depression may be, the cavity will be
filled if sediment be sufficiently abundant and cannot be more than tilled under
any conditions. In many known cases also subsidence has ceased jnst when the
load was greatest, the cavity being full.

Professor Emerson said:

The communication bears on the question as to whether the Pleistocene sub-
mergence of many northern lands was due to the weight of ice-sheets laid down
over these lands, and would seem to give an affirmative answer, except that it fails
to explain why the sinking lag^-d -,, long behind the loading.

Mr. McGee rejoined :

A principal purpose of the paper is to define the limitations of isostatic action
and to show that this cause is incompetent to produce the grander features of the
earth's surface exemplified by the Rocky mountains, the Gulf of Mexico and other
continents and seas — i. e., features due to the movement- classed as antecedent, —

yet that it is competent to produce such minor warping of the terrestrial crust as
that displayed by the present shores of the Gulf of Mexico and by ancient forma-
tions in many part- of the world. The fact of subsidence at a rate proportioned to
the length and activity of the tributary rivers in every important deposition tract
of the globe cannot be gainsaid, and to me it is absurd to hold that the length of
the Mississippi or the Amazon or the Indus is determined by the rate at which its
delta is sinking. The Netherland and New Jersey coasts are indeed subsiding
rapidly : yet it is to be remembered that by reason of geographic conditions, includ-
ing not only the configuration of coasts but the action of tides and currents, sedi-
mentation is in both eases confined to areas far smaller than those of degradation.
The theory of isostacy indeed makes for the doctrine of the persistency of rivers
and even of continents and oceans, but no more strongly than the facts of geology.
Rivers are the most persistent features of the earth, and the tendency of recent
research is to indicate the long, though not endless, persistence of the grander geo-
graphic features.

The second paper of the day was on —

PRE-GLACIAL DRAINAGE OF SUMMIT COUNTY, OHIO.
BY E. W. CLAYPOLE.

Remark- wereoffered by W. H. Sherzer, ( r. F. Wright and <i. K. Gilbert.

The following papers were next read :

OBSERVATIONS RELATING TO THE FORMATION OF LAKE GENEVA,

SWITZERLAND.

BY G. FREDERICK WRIGHT.

The paper was illustrated by charts and diagrams.

<;. F. WRIGHT — INTERGLACIAL SHELL-BEDS. 505

SUPPOSED INTERGLACIAL SHELL-BEDS IX SHROPSHIRE, ENGLAND.

BY G. FREDERICK WRIGHT.

Much Light has recently been shed upon the condition of the British isles during
the glacial period. The ice which covered so large a portion of them proceeded
from tour grand centers.

(li The first center was Scandinavia. After having moved across the shallow
bed of North sea, the ice from this center reached the eastern coast of England
from Flamboro head to Yarmouth, and advanced westward to a line connecting
Flamboro with London, covering Iloldcrness and a considerable portion of Lincoln.
Cambridge, Norfolk and Suffolk counties. The western limit, however, was quite
irregular; but Scandinavian bowlders are definitely recognized at various places
along the coast and in the interior. North of Bridlington, Scandinavian ice was
prevented from reaching the coast by the glacier-shed eastward from Scotland and
the northern uplands of England, which partly preoccupied the ground.

(2) The mountain plateau in northern Wales, of which Arenig, Mawrand Snow-
don are the culminating points, was a second center from which ice advanced into
England, moving eastward as far as Birmingham, a distance of about 100 miles.
This is evidenced by an interesting line of bowlders extending nearly north and
south, or nearly at right angles to the movement of the great Welsh glacier. This
line of bowlders extends from the vicinity of Litchfield through Birmingham and
southward to Bromsgrove. Not only are most of these bowlders definitely trace-
able to the Welsh mountains, but near Litchfield some have been found which
were brought from the Wrekin, the remnants of a Silurian mountain near "Welling-
ton in Shropshire, and about one-third of the distance between Litchfield and
Arenig.

Until quite recently it has been a puzzling circumstance that the glacial deposits
of western Staffordshire and northern Shropshire were characterized not by Welsh
bowlders but by bowlders that can be clearly traced to the Lake district in England
and to the southwestern portion of Scotland. Shap granite from Westmoreland
and granite from the Criffel mountains north of Solway firth abound in great
numbers in the till of this area. It is in the glacial deposits at Ketley, near Wel-
lington, that .Mr. Prentiss Baldwin and myself succeeded in finding the shell-bed
from which the accompanying specimens were obtained. As identified for me by
Professor Albert A. Wright, the shells are as follows:

Nassa reticulata ; one specimen. Common in England and France; also fossil from

the Miocene throughout Europe.
Titrritella (Communis ? ) ; many specimens. Smaller than the average hut similar

in sculpture i Britain has only one species of Turritella) vi/.. Communis).
Veiitalium; one specimen (tubular).
Lucina ' : one valve.
Fragments of ribbed >'<ir<lU<t (possibly Cardium).

These specimens were near together in a gravelly stratum two or three inches

t hick, which was underlain by a sandy deposit ■_'■"> or 30 feel thick and overlain by

from L0 to 15 feet of true till, containing scratched pebbles and small bowlders in

abundance, the bowlders being all either from the Lake district or from southern

Scotland. The hit in which this section svas shown has been extensively worked

506 PROCEEDINGS OV COLUMBUS MEETING.

to obtain the underlying sand, but nowhere did we see the stratum upon which the
sand rested, so thai we were unable to speak from observation of its nature; but
from the distribution of Welsh bowlders in the vicinity o'f Birmingham already
mentioned it is absolutely certain that Welsh ice had moved over this area previous

to the invasion of glaciers which started from southern Scotland. They are there-
fore without doubt what would properly be called interglacial beds. Their eleva-
tion above the sea. as given me by Dr. ( !rosskey and Mr. F. W. Martin, who accom-
panied us on the trip and conducted us to the locality, is in round numbers 500
feet. The Wrekin, two or three miles away, is a solitary peak in the Severn valley,
rising 1,335 feet above the sea. In other localities of the vicinity Dr. Crosskey had
found shells having a more arctic character than these in glacial deposits of similar
character about 700 feet above the sea.

In endeavoring to account for these shell-beds it will be necessary to take a still
more general view of the situation, and it is the more important to do this since
the explanation of this deposit is doubtless closely connected with that of similar
deposits found at still higher levels, namely, at an elevation of about 1,100 feet at
Macclesfield, a feu miles south of Manchester, and at 1,400 feet near Moel Tryfaen,
on the northwestern flank of Snowdon in Wales. On glancing at an orographic
map of England, it appears that between the northern part of the Welsh high-
lands and the southern projection of the Pennine chain in England there inter-
venes a valley, about 70 miles wide, known as the vale of Chester, running nearly
north ami smith, which is nowhere more than 500 feet above the sea. The shell-
beds under consideration occur near the head of the Severn valley at just about
the same height as the water-parting between the valleys of the Severn and the
Dee. A careful collection of facts made by Professor Percy F. Kendall concerning
the distribution of bake district and Scottish bowlders makes it clear that the vale
of Chester was occupied by the eastern branch of a confluent glacier which filled
the Irish sea, receiving vast contributions of ice from the two remaining centers
of glacial dispersion referred to above, namely, (3) the southwestern portion of
Scotland and northern England, and (4) Ireland.

bowlders from the Lake district in England moved westward into Morecambe
bay, where they were met by the movement from Scotland; while in the mean-
time glaciers from Ireland pushed eastward into the Irish sea until the whole basin
north of Wales was at length tilled with ice under sufficient head to abut against
the Welsh mountains and to push upward upon their northern flanks to a height
of more than 1,400 feet. But the main mass of ice was divided by the obstruction
and flowed in two streams, the one over Anglesea on the west into Saint George
channel to an indefinite distance, the other on the east through the vale of ( Jhester
almost to Birmingham, occupying the area already described as covered by bowlders
from northern EnglancLand Scotland. It was this movement which deposited the
till at Ketley and which, I believe, brought along from the bottom of the Irish sea
the shells which were there found by Mr. Baldwin. This is the theory advocated
by the late Professor Henry Carvill Lewis to account for the shell deposits found
at Macclesfield and Moel Tryfaen.

The considerations supporting this view are numerous : First, such shell-beds in
glacial deposits are strictly confined to areas known to have been occupied by glacial
ice which had previously moved over shallow sea-bottoms. At Ketley the bowlders
in the upper till all came from southwestern Scotland or the Lake district in Eng-
land by way of the Irish sea. Similar shell-beds found in the glacial deposits of

G. F. WRIGHT — INTERGLACIAL SHELL-BEDS. 507

eastern England arc confined to the area invaded by Scandinavian ice which moved
across the North sea bottom ; and between Flamboro head and Bridlington there
is very clear evidence that portions of the old sea-bottom were pushed up by the
ice to a height of nearly 300 feet. Such an instance was pointed out to me by Mr.
Lamplugh in the till overlying the chalk bluffs near Flamboro. Here it was clear
that a mass of clay, including shells, had been pushed along and drawn out by the
differential motion, and in some cases shells were found in the clay with the con-
cave side down, but tilled with sand, which had served to make it a compact mas-
capable of moving like any other pebble. These actual instances observed by Mr.
Lamplugh go very far to remove the antecedent objections which every one would
at first naturally urge to the theory. It should be noted also that the till at Mod
Tryfaen, at Macclesfield and at Ketley, as well as on the eastern coast of England,
contains numerous fragments of shells of the species found in the shell-beds. It is
easy to see. therefore, how they could be collected into thin beds by local currents
of water that must have arisen in connection with the melting of the glacial ice
which we know to have covered the locality where they were found.

Secondly, the shells in most of these beds do not represent any definite fauna.
The forms associated represent those living in cold water side by side with those
living in warm water, and rock-haunting species with sand or mud loving species.
On the Isle of Man, Professor Kendall has found in the glacial drift of the north-
ern shore representatives of Nassa serrata, Brocchi, a mollusk which is now charac-
teristic of the Mediterranean sea and cannot endure even the present temperate
climate of the Irish channel. It certainly could not have endured the rigors of a
glacial climate, even with the supposed amelioration during the so-called inter-
glacial epoch. The species, however, lived in the Irish sea during the Pliocene
period. On the theory that the shells were pushed up from the bottom of the sea
by the advancing ice, this and all similar cases are readily accounted for.

Thirdly, outside of the area in England which was not reached by glacial drift
there is a noteworthy absence of all the signs of submergence. "There are no true
sea beaches, no cliffs or sea-worn caves, no barnacle-encrusted rocks or rocks bored
by Pholas or Saxicava." Nor are any shells found in post-Tertiary deposits any-
where except in the area covered by ice which is known to have moved over a
sea-bottom. This is incredible if the subsidence supposed to have taken place really
occurred, since there must then have been numerous deep and quiet fjords specially
tit to harbor vast colonies of marine creatures, as such places are known to do at
the present day. In southern England the residuary soil upon the surface both of
the granite bosses of < lornwall and I (evon and over large areas of the chalk country
demonstrate the long-continued freedom of that area from subsidence. Nor are
1 here any positive evidences of subsidence of more than 200 or :;no feel in Scotland,
if even so much as t hat.

There would seem to remain, therefore, no way of accounting lor the shell-bed
at Ketley except on the theory of Professor Lewis that they were pushed along
with other transported material by the Irish sea glacier. If one inquires further
into the more specific processes by which the underlying sand was deposited and
the overlying till spread over it, i1 is impossible to give more than a tentative ex-
planation. The recenl studies of the Alaskan glaciers by Professor \U'\<\, Mr. Gush-
ing and Mr. Russell show us how complicated are the deposits near the front of a
uieat glacier. The ice itself becomes covered with debris and forms harriers ami
furnishec at once hoih the margins of small lake- and streams and the water and

508 PROCEEDINGS OF COLUMBUS MEETING.

silt to fill them : so that on a temporary advance it is easy enough to see how even
in an open valley all sorts of deposits may take place in rapid succession.

The bearing of these discoveries concerning the elevated shell-beds in the glacial
deposits of England is very significant with reference t<> the general theory of an
interglacial period. In fact, the principal necessity for the supposition of an inter-
glacial period in England disappears with this explanation. So far as theevidence
goes, the glacial period in England seems to have been a -rand unity, characterized
only by minor episodes and by periods of the prevalence, first, of the ice moving
from Scandinavia and the Welsh mountains and, secondly, of that which proceeded
more slowly from the sources of the great Irish-sea glacier. There is now left no
sufficient reason for interposing a vast interglacial subsidence between the preva-
lence of the ice coming from the first centers mentioned and that coming from the
other two. The upper till ami the lower, so far as found in England, is probably
the product not of two distinct glacial periods, hut of minor episodes in a single
period.

The Society then took a recess and visited the Columbus ( !lub in accep-
tance of the invitation extended the previous day by the colleagues of
Dr. Edward Orton.

At •'! o'clock p. m. the Society reassembled.

The first paper of the afternoon, read by W J McGee in the absence of
the author, was entitled —

THE CHAMPLAIN sUBMEPmONCE.

BY WARREN l" I'll AM.

(Abstract.)

Marine fossils in beds overlying the glacial drift prove that the northeastern part
of North America stood lower than now in the Champlain epoch — that is, the time
of departure of the last ice-sheet. This depression, which seems to have been pro-
duced by the vast weight of the ice, was bounded on the south approximately by
a line drawn from near the city of New York northeastward to Boston and onward
through Nova Scotia. When the ice-sheet was being withdrawn from this region
the country south of this line stood somewhat higher than now, as is shown by the
channels of streams that flowed away from the melting ice and ran across the
modified drift plains which form the southern shores of Long island, Martha's
Vineyard, Nantucket and cape Cod. A subsequent depression of the land there*
continuing perhaps uninterruptedly to the present time, has brought the sea into
these old river courses; hut north and northwest of this line the land at the time
of recession of the ice-sheet was lower than now and the const and estuaries were
more submerged by the sea. Fossiliferous beds of modified drift, supplied from
the melting ice-sheet and resting on the till, show that the vertical amount of the
marine submergence when the ice-sheet disappeared was 10 to 25 feet in the vicinity

WARREN ["IMIAM — THE CHAMPLAIN SUBMERGENCE. 509

of Boston and northeastward to cape Ann ; about 150 feet in the vicinity of Ports-
mouth, New Hampshire ; from Mo to about 300 feet along the coast of Maine and
southern New Brunswick; aboul to feet on the northwestern shore of Nova Scotia ;
thence increasing westward to 200 feet in the Bay of Chaleurs,375 feet in the Saint
Lawrence valley opposite the Saguenay, and 520 feet at Montreal ; 300 to 400 feet,
increasing from smith to north, along the basin of lake Champlain ; about 275 feet
at < >gdensburg, and 450 feet near the city of ( Htawa ; .'Kill to 500 feet on the country
southwest of James bay ; in Labrador little at the south, hut increasing northward
to 1,500 feet at Nachvak, according to [)r. Robert Bell, and in northern Greenland
and Grinnell land from L,000 to 2,000 feet.

That the land northward from Boston was so much lower while the ice-sheet was
being melted away is proved by the occurrence of fossil mollusks of far northern
range, including l.nin arctica, Gray, which is now found living only in arctic seas
where they receive muddy streams from existing glaciers and from the Greenland
ice-sheet. This species is plentiful in the stratified clays resting on the till in the
Saint Lawrence valley and in New Brunswick and Maine, extending southward to
Portsmouth, New Hampshire. But it is known that the land was elevated from
this depression to about its present height before the sea here became warm and the
southern mollusks, which exist as colonies in the Gulf of Saint Lawrence, migrated
thither, for these southern species are not included in the extensive lists of the
fossil fauna found in the beds overlying the till.

In the Saint Lawrence basin these marine deposits reach to the southern end of
lake Champlain, to Ogdensburg and Brockville, and at least to Pembi'oke and Allu-
mette island, in the Ottawa river, about 75 miles above the city of Ottawa. The
isthmus of ( Ihiegnecto, connecting Nova Scotia with New Brunswick, was submerged,
and the sea extended 50 to 100 miles up the valleys of the chief rivers of Maine and
New Brunswick.

From the Champlain submergence attending the departure of the ice the land
was raised somewhat higher than now; and its latest movement from New Jersey
to southern Greenland has been a moderate depression. The vertical amount of
t his post-glacial elevation above the present height and of the recent subsidence on
all the coast of New Jersey, New England and the eastern provinces of Canada is
known to have ranged from L0 feet to a maximum of at least 80 feet at the head of
t he hay of Fundy, as is attested in many places by stumps of forests, rooted where
they gre.Wj and by peat beds now submerged by the sea.

At the time of final melting of the ice-sheet this region, which before t he Lee age
had stood much higher than now. was depressed, ami the maximum amount of its
subsidence, as shown by marine fossils at Montreal and northwestward to Hudson
bay, was 500 to 600 feet. Subsequently our Atlantic coast has been re-elevated to

a height probably K' > feel greater than now; and during the recent e] h its latest

oscillation has been again downward, as when it was ice-covered^ The rate of de-
pression since the discovery of America has probably been I to 2 feet, or less, in a
hundred years. I n t he hasin of 1 1 udson bay, however, the observations of] >r. Bell
show that the re-elevation from the Champlain submergence is still in progress, its
rate, according to his estimate, reaching probably 5 to 7 feet during each century.

Turning to the glaciated regions of Europe, we find similarly thai the countries
which wire ice-covered, after having been much higher before the ice accumu-
lation, as shown by fjords, were depressed somewhal below their present height
when the ice disappeared. The supposed great submergence, however, up to 1,21 0

l.\ I \ -Bi ii Soc, V»l., Vol. 3, 1891.

510 PROCEEDINGS OF COLUMBUS MEETING.

and 1,500 feet or more, which lias been claimed by British geologists for northern
Wales, north western England and a part of Ireland, on the evidence of marine
shells and fragments of shells in glacially transported deposits, is shown by Belt,
Goodchild, Lewis and others to be untenable. Indeed, these fossils, not lying in
the place where they were living, give no proof of any depression of the land, since
they have been brought by currents of the ire-sheet moving across the bed of the
Irish sea. Bui it is clearly known by other evidence, as raised beaches and fossil-
iferous marine sediments, that large portions of Great Britain and Ireland were
slightly depressed under their burden of ice and have been since uplifted to a ver-
tical extent ranging probably up to a maximum of about 300 feet.

In Scandinavia the valuable observations and studies of Baron de Geer have
supplied lines of equal depression of the land at the time of the melting away of
the ice. This region of greatest thickness of the European ice-sheet is found to
have been depressed to an increasing extent from the outer portions toward the
interior. The lowest limit of the submergence, at the southern extremity of
Sweden, is no more than 70 feet above the present sea-level, and in northeastern
Denmark it diminishes to zero; but northward it increases to an observed amount
of about SOI) feet on the western shore of the Gulf of Bothnia, near latitude 63°.
Along the coast of Norway it ranges from 200 feet to nearly 600 feet, excepting far
northward, near North cape, where it decreases to about 100 feet. In proportion
with this observed range of the subsidence on the coast of Scandinavia, its amount
in the center of the country was probably 1,000 feet.

A very interesting history of the post-glacial oscillations of southern Sweden
has been also ascertained by Baron de Geer, which seems to be closely like the
post-glacial movements of the northeastern border of North America. As on our
Atlantic coast, the uplift from the Champlain submergence in that part of Sweden
raised the country higher than now. The extent of this uplift appears to have
been about 100 feet on the area between Denmark and Sweden, closing the entrance
to the Baltic sea, which became for some time a great fresh-water lake. After this
another depression of that region ensued, opening a deeper passage into the Baltic
than now, giving to this body of brackish water a considerably higher degree of
saltness than at present, with the admission of several marine mollusks, notably
TAttorina litorea, L., which are found fossil in the beds formed during this second
and smaller submergence, but are not living in the Baltic to-day. Thus far the
movements of southern Sweden are paralleled by the post-glacial oscillations of
New England and eastern Canada ; but a second uplifting of this part of Sweden
is now taking place, whereas no corresponding movement has begun on our Atlantic
border. It seems to be suggested, however, that it may yet ensue. The subsidence has
ceased or become exceedingly slow in eastern New England, while it still continues
at a measurable rate in New Jersey, Cape Breton island, and southern Greenland.
So extensive agreement on opposite sides of the Atlantic in the oscillations of
the land while it was ice-covered, and since the departure of the ice-sheets, has
probably resulted from similar causes, namely, the pressure of the ice-weight and
the resilience of the earth's crust when it was unburdened. The restoration of
isostatic equilibrium in each country is attended by minor oscillations, the condi-
tions requisite for repose being over-passed by the early reelevation of outer por-
tions of each of these great glaciated areas.

In view of this harmony in the epeirogenic movements of the two continents
during the Glacial, Champlain, and Recent periods, it seems evident that the close

WARREN I I'll A M — THE CHAMPLAIN SUBMERGENCE. 511

of the Iff age was not long ago, geologically speaking, for equilibrium of the
disturbed areas has not yet been restored. Furthermore, the close parallelism in
the stages of progress toward repose indicates nearly the same time for the' end of
the Glacial period on both continents, and approximate synchronism in the pen-
dulum-like series of post-glacial oscillations.

Remarks were made by B. K. Emerson.

The next paper was presented in abstract by J. S. Diller —

THE ELEOLITE-SYENITE OF LITCHFIELD, MAINE, AND HAWES' HORNBLENDE-
SYENITE FROM RED HILL, NEW HAMPSHIRE.

BY W. s. BAYLEY.

The paper was discussed by J. E. Wolff, B. K. Emerson and J. S.
Diller. It is printed as pages 231-2.52, with plate 7, of this volume.

The next paper was read by W J McGee, the author being absent:

NOTE OX THE MIDDLETON FORMATION OF TENNESSEE, MISSISSIPPI AND

ALABAMA.

BY JAMES M. SAFFORD.

It i- known that in September last a party of geologists organized and carried out
an expedition having for its object the reexamination and study of typical sections
in Tennessee, Mississippi, Alabama and other southwestern states. The expedi-
tion, organized in Washington under able leadership, was a most successful one
and will be long remembered tor the pleasure it afforded all members of the party.
Its history lias been given elsewhere, and need not hi' repeated here.

The party stopped lor a time at < >xford, the site of the university of Mississippi.
While here the writer caught sight of" some peculiar rock fragments containing
Eocene shells, which he thoughl must have come from localities known to him in
Tennessee. Dr. Hilgard, however, who was one of the party ami near at hand,
-aid they were from Mississippi, and pointed out the page in his "Agriculture
and Geology of Mississippi " (1860) on which the rock from which they came is
described. The rods is that indicated as '-clay-sandstone." division number 2 of
t he section on page II-. I >r. Eugene A. Smith, also a member of th ■ party, informed
ns that the same formation occurs in Alabama.

The Tennessee rock is strikingly like that of .Mississippi ami could not be told
from it. [t occurs in Tennessee, in Hardeman county, a1 a number of points. One
of these is the town of Middletomon the Memphis and Charleston railroad, and
for many years I have spoken of it as the Middleton bed.

And so it was that three of us, representing a- many state- -Tennessee, Missis-
sippi and Alabama -were, by a happy accident, thrown together and made to -,■,■
that our several rocks were one and the same formation.

The particular and characteristic rock referred to above is rarelj more than three
'eet i hick, hut it ha- associated with it a -roup of layers of much greater thickness.
The group hat" importance in the fact that it is the lowest Eocene in the states

512 PROCEEDINGS OF COLUMBUS MEETING.

mentioned. With'the concurrence of Dr. Hilgard and Dr. Smith, I propose for it
the name of Middlelon formation.

An article on the formation is in the hands of the editors of the American Geol-
ogist for publication. This will be followed by others.

Mr. McGee also read the next paper for the author, who was absent:

THE AGE \XI> ORIGIN OF THE LAFAYETTE FORMATION.
BY E. \V. HILGARD.

The paper is printed in the American Journal of Science, 3d series,
volume xliii. 1892. pages 389-402.

The following paper was read by title:

pal.i:aster etch a u is, hall.

BY A. II. COLE.

The fossil which calls forth the following observations is an impression of the
oral surface of a starfish found in July last in the Hamilton shales in the quarry
belonging to ( Jolgate university at Hamilton. New York.

The fossil has been compared with the type specimen from which Dr. Hall's
species was described and figured. As it agrees with the type in general, though
varying from the description in certain important characters, and by reason of its
perfect preservation reveals hitherto unknown details of structure, it seems best to
review the original description in so far as it relates to the oral surface.

"PALjEASTER EUCHARIS (11. sA*

■■ Body rather large : the largest individual being one inch and seven-eighths from the center of

the body to tl xtremities of the rays; the whole having a robusi aspect; rays aeutely pointed at

the extremity.

"Ventral surface having deep ambulaeral grooves, bordered by two ranges of strongly tuber-
culose plates; the outer marginal range consisting of twenty-seven or twenty-eight plates, besides
a large, round, terminal or axillary plate ; the others are wider than long in the basal portion of
the ray, becoming gradually shorter toward the extremity, where they are rounded.

"All the marginal plates are visible from the upper side, and usually appear as an additional
range of plates on each margin of the ray, making five with the three properly belonging to the
upper surface.

•'The inner range bordering the ambulacra (adambulacral plates) are -mailer than the marginal
plates, about thirty-eight to forty in number; the basal or oral plate- are triangular, those of the
adjacent ray- uniting by their longer margin-, ami with a single minute plate situated at these
points.

- The plate- of the exterior surface, both upper and lower, present a granulose or striato-grami-
lose surface, which appear- to have been produced by short setae or spines, and at the angle- of
the rays the marginal plate- are armed by a few spines, which are a- long or longer than the
transverse diameter of the plati s.

"Ambulacra composed of a double range of short broad poral plates ossicula I, equal in number
to the adambulacral plate.-: their outer end- excavated on the posterior border, forming a com-
paratively large pore, |us( within its junction with the adambulacral plate. There appears to have
been but one range of pores in each set of ossicula, but these are large, distinct, and pas- between
the plates.

*20th Ann. Rep. Y V. state < labinet of X.,t. Hist.. 18G7, p. 287, pi. ix. tigs. :;. :;■ . :;.< and I.

A. II. COLE PAL-EASTER EVCHARIS, HALL. 513

-In the collection there is an impression of a single ambulacra! area of this species, which is
spread open laterally, and measures about two and a half inches in length by nearly three-fourth a
of an inch in width in the middle, broadly petaloid in shape, and showing the form and number of
the poral plates, with the posit inn of the pores and their junction with the adambulaeral plates."

The specimen in hand differs from this description in the following particulars :
The terminal <>r axillary plate of the marginal range is elliptical in form, with
its major axis directed toward the adjacent reentrant angle. Its surface is granuL isl-
and bears three short, thick, blunt pointed spines. The marginal plates bordering
each reentrant angle bear similar but more slender spines, which are not "as long
as the transverse diameter of the plates." The spines arc arranged in a row near
the distal margin of the plates and number five on the plates at the angle, the
number and size decreasing until they disappear at the sixth or seventh plate from
the angle. All the marginal plates are nearly smooth on the free margin and be-
come gradually more granulose toward the line of junction with the adambulaeral
plates. The margins of the rays show in three places that the ventral marginal
plates were visible from above, agreeing with the original description.

The adambulaeral plates are apparently less numerous than stated in the original
description, and "the single minute plate" at the points of the pairs of the oral
plates is visible in this specimen and is armed with two relatively long, slender
spines which are apparently but a part of the full armature. The adambulaeral
plates, including the triangular oral plates, bear well defined spines, which are
shorter than the diameter of the plates to which they are attached. Each plate
bears two spines so near to the distal margin that the impressions of the short and
obtusely pointed spines frequently bridge the well defined groove between the
adjacent adambulaeral plates and terminate near the proximal margin of the next
plate. The spines decrease in size toward the end of the ray and a few plates show
only one spine. The plates of this range are thick, equaling two-thirds to three-
fourths the depth of the groove. The vertical angles of the faces forming the
lateral walls of the groove are beveled, so that lateral extensions of the groove are
formed between each two plates on the same side. These lateral expansions are
narrow and shallow at the oral surface, deeper and wider inward ; so that the faces
of the adambulaeral plates near their junction with the poral plates are reduced to
a narrow edge which projects inward and nearly touches the corresponding plate

on the other side of the groove. The general appearance of the fossil as well as the
outline of the rays at the points where the broken block presents a transverse sec-
tion of them indicates that the plates have their normal position, not having
suffered distortion by pressure.
The ambulacra! plates are shown by a well defined mold of their under or

external surfaces. The soft matrix which tilled the ambulacra! furrow pressed

upon the membranes connecting the ambulacral plates and occupying their pur.-,
and as these membranes decayed it was forced by gentle pressure into the pores
and between the edged of the plates. The mold of the groove is less than one-
eighth of an inch in width in a ray measuring five-eighths at its base. The upper
Burface of the mold hear- a narrow longitudinal median ridge which marks the
junction of the two ranges of ambulacra! plates, similar transverse ridges, w hich
are continuous with the lines marking the junction of the inner faces of the
adambulaeral plates, mark the proximal and distal margins of the ambulacral

plates. Theseridgesd t cross at a righl angle to the median line, but include

between their proximal sides an angle of aboul 125°. These ridges indicate thai
the ambulacral and adambulaeral plate- were equal in number, and thai the former

514 PROCEEDINGS OF COLUMBUS MEETING.

were united in pairs along a straight median line rather than in an alternate right
and left arrangement along a zigzag line, as is shown in Dr. Hall's figures. The
pores described as being " excavated in the posterior border of the ambulacral
plates and just within their junction with the adambulacral plates" are not
clearly shown on this specimen, although then' are irregular and inconstant mark-
ings at some of the points of the molds of the lateral extensions of the groove.
A series of pores near the median line is indicated by a series of small rounded
prominences on each siile of the median ridge and very close to it. These promi-
nences are opposite the lateral expansions of the groove, and one is found on the
mold of each ambulacral plate. The pores appear to have been perforations very
near the edges of the plates, or excavations in their margins.

Another specimen of the same species from the same quarry, which has recently
been loaned to me for examination, shows the spines on the axillary and adam-
bulacral plates, but the imperfect preservation of the fossil renders them less dis-
tinct. The mechanically reproduced photograph (plate 15) accompanying this
paper shows that one ray has an obtusely rounded extremity which was, at first,
considered as possibly a normal character, as it is in Palseaster granulosa. The
finding of spines on the oral surface also seemed to ally the specimen with P.
granulosa ; but the presence of spines, as in the specimen described, together with
acutely pointed rays, both of which characters are seen in the second specimen
from the same quarry, are conclusive evidence that the specimen is P. eucharis.

These fossils are extremely rare in the Hamilton shales. I have been able to
learn of the finding of only four in this vicinity, or, including the one mentioned
by Dr. Hall, the number known is five. Other localities have contributed a small
number.

In the absence of the author the following paper was presented in
abstract by J. E. Wolff:

ON THE STRUCTURE AND AGE OF THE STOCKBRIDGE LIMESTONE IN THE

VERMONT VALLEY.

BY T. NELSON DALE.

( 'ontents.

Page.

Introduction .".14

A real Geology 515

Structure ami Age 51li

Sections 516

The upper Part of the Limestone and the Schist .M7

The Fault M7

KTm inn'. * 518

I NTRODUOTION.

Between the Green mountain range and the Taconic range and on the western
side of the Vermont valley lies a ridge which, beginning with Pine lull in Rutland,
extends southward through the towns of Clarendon and Wallingford about 24 miles

Bull. Geol. Soe. Am.

Vol. 3. 1891. PI.

I'AL/EASTEH EUCHARIS, HALL -2'.. DIAM.

T. D. DALE — THE STOCKBRIDGE LIMESTONE. 515

|u I >;i 11 1 >\ hill in Danby.* Its altitude above Otter creek ranges from about 400 to
l.ioo feet.

This ridge was described by the geologists of the Vermonl survey t as an anticlinal
of quartzite flanked both on the cast and west in places by Talcoid schists, in others
by the Eolian limestone, and the schists forming its southern end were represented
as cut off from those of the Dorset mountain mass by an east -west fault.

Professor ('. 11. Hitchcock in his sections! omits the anticlinal structure from the
quartzite, calls the schists on the eastern side Cambrian slates, and the limestone
on both sides ( 'amhro-Silurian.

Mr. J. E. Wolff, in his paper read before this Society last December, shows the
composition of the northern end of the ridge to be as follows, beginning at the
eastern side: (1) Cambrian Limestone overlying (2) Cambrian quartzite and its
associated conglomerates and gneisses; then (.'!) schist overlying (4) the lower
Silurian limestone of the Center Rutland valley, lie also shows the continuity at
the surface id' the quartzite of the ridge with that of the western flank of the Green
mountain range. He would explain the abnormal relations between the quartzite
of the ridee and the Stockbridare limestone on the west by "A great thrust nlane by
w Inch the Cambrian is made to overlie the lower Silurian limestone." \

During the past summer, after examining Mr. Wolffs localities and finding, as he
says, that they do not yield a decisive proof of such a thrust plane. ! I crossed the
ridge at several points between Rutland and Danby to find a more favorable
locality. Such an one was found in Clarendon, where a deep and wide saddle in
the ridge afforded many excellent outcrops.

A contour map on a scale large enough to show the details in the wooded area-
was hereof prime importance. Such a map was therefore made, and a reduced
copy of it is here given (plate 16). In addition to the usual symbols for the strike
and dip and pitch of the stratification-foliation, those used by Dr. II. Reusch, of
Christ iania.': to indicate the strike and dip of the cleavage-foliation have been em-
ployed.

A REAL < rEOLOGY.

The areal geology is simple. The eastern half of the ridge consists of the
quartzite, conglomerates and schists of the Cambrian i including, perhaps, some
older gneisses and eruptives), coming in contact in the valley on the east at one or
two points with the Stockbridge limestone. This quartzite is in contact on the
west, along the axis of the ridge, with limestone in the lower pari of the saddle,
and with a schist overlying that limestone in the higher parts both north and
south. In the southern half of the map t he limestone area is only 650 feet wide,
and the schist tapers to about 250 feet. Both schist and limestone are here fol-
lowed westwardiy by another mass of quartzite, which dips normally under the
limestone of t he Ti mi ion t h valley, which is continuous with thai of center b'ut land.

♦ Danby hill lie-- two miles north of the northern purl of ! > . » t- — . • r i ntain, which in the Vermonl

report is called I (nnby mountain.

f Report on the Geology of Vermonl by B. and B. and. C. H. Hitchcock and \ D. Hager. 1801 :
vol. 1. p. 350, 863; vol. ii. p. 703, pi. \ iii. fig. - : pi. x\ i. sec. iv . \ .

Geol. sections across N. II. and Vt. : Bull. \in. Mus. Nat. Hist., nil. I, no. ii, 1884, pi. Ii
i \ . \ . \ i.

ji" On the Lower Cambrian \ge of the Stockbridge Limestone." Bull. Geol - • V in., vol.
pp. :;:;l ;

I '". cit., p. 337.

• Neues .1 dull. I'm- Min . Geol , etc, V Beilageband, Stuttgart, 1887

;i6

PROCEEDINGS OF COLUMBUS MEETING.

Structure and Age.

Sections. — The five sections herewith (figure 5) show the structural relations. In
section .1, which crosses the lowest part of the saddle, the Cambrian quartzite forms
on the eastern side an anticlinal and a synclinal, the latter infolding some 65 feet
of the lower part of the Stockbridge limestone. West of this, owing to a fault, a
block of this limestone about 650 feet wide has slidden down between two masses
of quartzite. Beyond the quartzite dips normally under the limestone, and this
includes a bed 25 feet thick and about a quarter of a mile long filled with fossils,
determined by Mr, ('. I>. Walcott as Hyolitlies americamis, Billings,* with the fol-
lowing species doubtful : //. imper, IT. communis and //. similis (very doubtful) ; the
whole indicating, as he writes, t '"The upper horizon of the lower Cambrian or
Olenellns zone." As there are about 470 feet of limestone between this bed and
the underlying quartzite, that much of the limestone must be regarded as Cam-

FAULT
CLEAVA&E ;

s;i. s.c.KCi.c.

CftmK Quartitte

FAULT

t^. cuavaie ;

fj" Lonqil".

CTTf* CR.

Qv&yCh t e

L'*n»sronp

Figure 5. — Sections through Ruttand-Dariby Ridge.

brian. These pteropods appear more frequently in transverse sections, but also in
every sort of section. Each individual or fragment generally forms the center of a
concretion-like body from ] to 1 inch in diameter (figure 6). These bodies, how-
ever, require further study. The rock is bluish-gray. The oolitic structure appears
best on weathered surfaces.

In section />', about a quarter of a mile north of .1, the eastern fault-plane alone
appears, the western having died out or merged into it. Mere the quartzite shows
a synclinal and an anticlinal, and is broughl by the fault to the level of the schists
overlying the limestone.

* E. Billings— " On some New Species of Paleozoic Fossils: Canadian Naturalist, Dec, 1871, re-
printed in Am.Journ. Sei., 3d ser., vol. iii, 1872, p. 352; C. D. Walcott— " Studies on the Cambrian
Fauna of North America": Bull. 30 IT. S. Geol. Surv., 1880, p. 132, pi. xiii; also -The Fauna ofthe
Lower Cambrian or ( Henellus Zone" : 10th Ann. Rep. IT. S. Geol. Surv., 1890, p. 1520, pi. Ixxv.

f November 13, L891 .

T. X. DALE — THE STOCKBRIDGE LIMESTONE.

>1 t

In section ( ', about three-quarters of a mile farther norl hi ward, the quartzite over-
lies the schist.*

In section D, south of .1 and about half a mile south of the deepest part of the
saddle, a block of the schist which belongs over the limestone is wedged in between
quartzite masses. The structure is like that in section .1. but occurs higher up the
hill where the schists have escaped erosion.

Section E is longitudinal, from the deepest part of the saddle northward. Owing
to the northerly pitch of the anticlinal at this point, together with the deep erosion
of the ridge, the entire thickness of the limestone from the quartzite to the schist
is here exposed along a north-south line, and the three rocks are seen in their
normal relations with well observed contacts. This section tlm- yields a measure-

Figure G.—Structurt of Hyolith.es Limestone.

ment of the limestone, which amount- to from 1,001) to 1,400 feet, according as the
average pitch is taken as 25° or 35°; 1,200 feet is probably correct.

Tin upper Part of thr Limestone "ml tin- Schist. — The northeastern corner of the map
(plate Ki; overlaps the extreme southern end of Mr. Wolff's map and includes the
fossil locality given by him southeast of Clarendon Springs, where Mr. Aug. F.
Foerste found in a sandy limestone "crinoid stems and plates and a small blanch-
ing bryozoan with large cells. "t This locality (339 on map) is in a small lenticular
area of limestone surrounded by schist, the former of which may be regarded either
as representing the schist by different sedimentation, and thus of the same age as the
schist, or as a minor anticlinal in the uppermost part of the Stockbridge limestone.
During the past summer Mr. Foerste found fragments of crinoid columns and a
Heliolites f (Walcott's determination) in a similar but smaller limestone area 260
on map) within a few feet of the fault. This from its position can hardly belong
to the limestone, but must represent the age of the schist. Mr. Foerste also found
on the eastern side of the ridge, near South Wallingford, in the limestone near the
schist, besides the usual crinoid stems, the following: Streptelasma, sp. ? ; a coral
much like Heliolites; and cross-sections of strophomenoid shells — all determine. I
by Mr. Walcott, who refers the fossils generally to the Chazy-Trenton-Lorraine
faunas.

from all these facts it follows that the upper part of the limestone and certainly

a portion of t he overlying schist are of Lower Silurian age.

'/'/,, /■'(in/I. — As will he seen by examining the sections, the amount of displace-
ment along the fault plane equals the entire thickness of the limestone, besides
aboul 300 feet of the overlying schists.;.,.. 1,500 feet. The line of the fault is
marked in places by large quartz veins and on Pine hill by eruptives. The fault

can he followed to a point west of South Wallingford. < Ml the southern side of

• The structure here m >>• even be more extreme than 9hown in the section.

1 Op. oil ,p 131

LXX— Bi i,i.. fJnoi . Boi . Am.. Vol. ::. 1891.

518 PROCEEDINGS OF COLUMBUS MEETING.

Mill brook, at the northern foot of the Dorset mountain mass, the quartzite and
blue quartz conglomerate reappear, although not shown on the Vermont report, with
the lower Silurian schists in contact on the west. This fault thus trends at righl
angles to the east-west fault described in that report.

The obscurity of the fault on the ridge at many points is due to its bringing
together certain dark mica (sericite) schists, consisting of alternating more quartzose
with more micaceous laminae, which belong to the Cambrian quartzite series, on
the cast, with the dark but not banded and generally more or less graphitic sericite
schists of the lower Silurian on the west. The fault is also further obscured by a
cleavage-foliation in both schists, dipping at a high angle eastward and parallel to
the fault plane, whereas the stratification of both Cambrian and Silurian schists,
except in rare instances, dips westward in low undulations, as can be made out here
and there and as the vertical and horizontal relations of the limestone and the
Silurian schist at Clarendon necessitate in the case of the latter.

Resume.

Tlie Rutland-Dauby ridge is a complex anticlinal of gneiss and Cambrian
quartzite, conglomerate and schist flanked by Cambrian limestone and lower
Silurian limestone ami schist. The upper part of the Cambrian quartzite on its
western side dips under the base of the limestone of the Tinmouth, Center Rutland
valley, and on it- eastern side, as shown by Mr. Wolff at Pine hill, under the base
of the limestone of the Vermont valley. ,

Mr. Wolff has shown the Cambrian age of the base of the limestone on the eastern
side, ami this paper shows the corresponding fact on the western side. Admitting
that the schist overlies the Stockbridge limestone in these valleys at about the same
horizon, the entire thickness of that limestone in this part of Vermont maybe
reckoned at 1,200 feet, and the Hyolithesbed at West Clarendon shows that about
470 feet of the lower part of this belong to the ( 'ambrian ; but the upper part of the
Stockbridge limestone has been shown by Reverend Augustus Wing's fossil locali-
ties at West Rutland* and Mr. Foerste's collections at (enter Rutland, Clarendon
Springs and South WaUingford to be of Lower Silurian age, and to this age belongs
also a part, if not all, of the overlying mass of schist.

Owing to a fault extending from Pine hill in Rutland to WaUingford, about 16
miles, causing a displacement measured at Clarendon as l.oiio feet, the Cambrian
quartzite and conglomerate and schist have been brought up to the level of the
bower Silurian schists, which latter they in one place overlie. It is owing to the
anticlinal structure, complicated by faults, of the Rutland-Danby ridge that at some
points the base of the Stockbridge limestone with its Cambrian fauna, while at
others, not far oil', the top with its Lower Silurian fauna, is alone exposed.

besides these general results, many minor facts were established and the explora-
tions were continued southward on the Dorset mountain mass, but they are not
yet sufficiently elaborated for publication.

Professor B. K. Emerson spoke as follows:

It is a pleasure to express my high appreciation of the importance of the results
reached in tins investigation and of the care and fullness with which it was con-

* "An Account of the Discoveries in Vermont Geology of the Reverend Augustus Wing," by J. D.
Dana: Am. Journ. 9ci., :i'l ser., vol. xiii, 1 s 7 7 . p. 332.

BULL GLOL SOC AM.

VO L. 3. 1892. PL_I6.

T. X. DALE — THE STOCKBRIDGE LIMESTONE. 519

ducted. The bearing of Mr. Dale's excellent work is closely related to the results
detailed in the paper just read by Mr, Hobbs. Sftnilar phenomena to those de-
scribed by both gentlemen occur in the Cambrian gneisses at the large quarries at
Monson, Massachusetts, where it has been my fortune recently to discover traces
of a conglomeratic structure. The distortion of the pebbles consists here in a flat-
tening at right angles to the pressure (east to west) and a great elongation in the
vertical direction, with a lesser change in the third direction (north to south).
The tension in this latter direction expresses itself in an expansion of the blocks
from north to south when quarried, and which is so strong as to cause great blocks
to crack off from the face of the quarry under favorable circumstances with loud
detonations. This tension is evidently connected with mountain-making com-
pression. These interesting phenomena are fully described in the publications of
Professor Xiles. chiefly in the Proceedings of the Boston Society of .Natural History.

The last paper was read by title:

A CONTRIBUTION TO THE GEOLOGY OP THE GREAT PLAINS.

BY ROBERT HAY.

It is a fact that the study of the geology of the Plains has in times past been
slighted by geologists. As soon as it was possible to travel quickly to the Rocky
mountains, thither the naturalists of all sorts went. The upturn of the strata on
their flanks made it possible to study rocks of almost the whole geologic scale in
areas of only a few miles in extent. The neighboring Archean rocks, the faults
and metamorphoses, were too fascinating to leave for the slower investigations of

the valleys of the region of the Plains. Still all who crossed the Plains made some
observations, and little'by little knowledge was acquired that made some general-
izations possible. We wish here to add some facts which, with previous knowl-
edge, will possibly justify a few other generalizations.

From the southern slope of the Black hills, in Dakota, to the Panhandle of Texas,
and from the lOllth to the lollh meridian, the surface terrane of the Plains on the
level interfluvial spaces is a fawn-colored calcareous and arenaceous clay, which is
of late Tertiary age in its oldest parts and probably shades into post-Pleistocene on
its eastern boundaries. It includesthe Equus beds of Cope, but usually is barren of
fossils. It varies from 3 or 4 feet to 200 feel thick. It isthinnedoff by Quaternary
erosion on the slopes of the valleys. '1 "his erosion has also leached out in many
places all its calcareous and argillaceous ingredients, and left its sand to be piled
into eolian dunes. The bottom of this Plains marl rests on a much eroded surface,
which is mostly formed of another Tertiary formation, hut in places the immedi-
ately subjacent mck is some ( Iretaceous terrane.

This Tertiary formation under the marl is. in the northern part, the White River
beds, which in Pine ridge attain a thickness of 7011 or 800 feet. South of the 10th

parallel and east of the 103d meridian this gives place to the Loup Fork, whicli
rests on the Cretaceous without the intervention of the White River beds, and
which is characteristically developed toward the northeast in Nebraska. In this
region, from about the 1 1st parallel to the 35th, the Loup Pork has a \ arying thick-
ness of from a very few feet or a mere trace to nearly 100 feet. These thicknesses

are those found in outcrops in the valleys of lern erosion. We cannot he certain

of it elsewhere; we can only infer approximately. It is the main water-bearing

520 PROCEEDINGS, OF COLUMBUS MEETING.

stratum of this region of the Plains, so that wells piercing it never go through it.
As with the marl, erosion has left sand behind, which aids the formation of dunes.
I have called these terranes the Tertiary grit.

The bottom of the Neocene formation — White River or Loup Fork — rests on a
much eroded surface of Mesozoic strata. This pre-Neocene erosion is shown, as well
as the later one, in all the deeper valleys of the Plains, and it is manifest that the
two succeeding erosions have largely cut down the valleys on the old pre-Neocene
lines.

This being true, it is also true that some of the pre-Neocene and mid-Neocene
valleys have not been reopened by modern erosion. They are to be traced by
lines of basin-like depressions, and in Nebraska there an1 examples of modern
erosion having cut them transversely.

When beneath the Tertiaries we examine the subjacent Mesozoic formations;
we find a thickening of them toward the north and northwest. This is what we
note in the Tertiaries. "Whether this is due to original deposition or to the pre-
Neocene erosion, or to both, cannot lie stated certainly; but it is a fact that from
Platte river southward on the 102d or 100th meridian the outcrops of the Mesozoic
strata in the river valleys are in descending order. Thus, on the 100th meridian
we have in —

Republican valley — Montana shales.

Sappa " Colorado group — Niobrara.

Prairie Dog

Solomon " " " (lower part).

Smoky

Walnut " " " Benton.

Saw Log " " " Benton resting on Dakota.

Arkansas " not shown.

( 'rooked creek " Trinity.

Cimarron " Red beds.

The valley of the Canadian and Red rivers in the Panhandle of Texas, with a
total section of 1,000 feet, shows nothing higher than the Trinity (at least in this
longitude). This Cretaceous deposit is, as farther northward, overlain by the
Tertiaries.

< )n the 102d meridian erosion has not proceeded so far and the outcrops are fewer.
A little east of it we have in —

Republican valley — Montana shales.

Smoky " no outcrop.

Whitewoman " Colorado — Niobrara (very slight outcrop).

Arkansas " " Benton.

Bear creek " Dakota.

Cimarron " Trinity.

This relation is represented graphically in figure 7. Reduced to scale for the
known elevation, this diagram would show undulations of the strata that can only
at present be taken as approximate to the reality till we have a more complete sur-
face survey. It is not meant to affirm that the Dakota rests on the Trinity, but on
the 102d meridian it is the next southerly outcrop. Further eastward it is known
that shell-beds with Gryphea, Turretelki, etc lie above the Trinity sands.

ROBERT HAY — GEOLOGY OF THE PLAINS.

521

In the region of the Black hills the Cretaceous rocks are broughl to view again
in descending order northward. North of the hills they disappear in reverse order,
and northeastward they thicken considerably, the Laramie of the lower Yellow-
stone and the Little Missouri "bad lands" attaining great thickness.

Two facts in the topography of the mid-Plains region are to be noted : ( 1) there
is a decided valley between the Plains and the mountains, the former having a steep
western escarpment from near Pueblo to near Cheyenne, Wyoming. This valley
has its Tertiary formations, which are not here treated of. We would emphasize
the fact that in the region above described the Plains formations are cut off from
contact with the mountains. Running westward from Cheyenne is a ridge which
constitutes the highest part of the Plains, running up to nearly 7,000 feet, and on
this ridge the Plains formations abut against the mountains, overlapping the tilted
Mesozoic and Paleozoic formations and resting on the granite. There are traces —
the merest fragmentary patches — of this overlap down all the line of the foothills
to Canyon City, but this ridge in south Wyoming is apparently the only place
where modern erosion has not cut it away. It is the water-shed between the North
Platte and South Platte drainage, and north of this, down the Chugwater to the
North Platte, the western escarpment of the Plains is 1,0(10 feet high. (2) The
other fact is that the streams between the Platte and the Arkansas and some both
south and north of those rivers have their sources and courses on the Plains. Their

Km. i i:r. 7. — General Section on tin- 102d Meridian.

valleys, from 200 to 500 feet helow the level of the interfluvial plains, have been cut
by the meteoric agencies of the region, unaided by the mountain snows, and they
owe their perrenia] supply of water to the springs that issue from the Tertiary grit.
We are not treating hereof the mauvaises terres of the Dakotas, but these Tertiary
terranes in their weathering have, in, the valleys of Nebraska and Kansas, been
carved into fantastic forms of castles and buttes and palisades which vary by a
local picturesqueness the intense monotony of the plains.

We desire here to call attention to the lines of investigation that w ill aid in the
elucidation of the phenomena of the plains. We have mentioned that erosion has
nol proceeded -n Ear (in the mid-Plains region) on the I02dason the 100th meridian ;

I ml near the former line there are outcrops in many of the valleys which show the

formations subjacenl to the Tertiaries. Surveys on the lOlsl meridian would, in
the Panhandle of Texas, cross the gashes cul by the Canadian and Red rivers to
the depth of i.oiiii feel : across Nebraska the same line would shoM very little out-
crop of Cretaceous rocks. A survey on the limth meridian from Dakota to the Rio
Grande would reveal largely the structure of the plains, and shorter lines north.
and-south further westward would show the variations of structure that characterize
part in ilar regions and the varying amount of the forces thai have combined in the
modern era to give the presenl physical characteristics to the region of the < rreal

Plain-.

o-22

PROCEEDINGS OK COLUMBUS MEETING.

Pending the close of the meeting, the following resolutions, presented
by B. K. Emerson, were unanimously adopted :

"Resolved, That the thanks of the Geological Society of America be tendered —

"To the authorities of the State of Ohio for the use of the Hall of the House of
Representatives during the fourth annual meeting of this Society ;

"To the Honorable < reorge J. Karb, Mayor of the city of Columbus, for his cordial
welcome to the Society and his generous tender of the hospitality of the city ;

"To the officers of the Ohio State University for their hearty welcome to this
Society and their personal efforts to make the meeting a success;

" To the Local Reception Committee, consisting of I). S. Kellicott, W. R. Lazenby,
X. W. Lord, F. W. Sperr and H. A. Surface, for their personal interest in the meet-
ing and their labor and solicitude, which contributed greatly to its pleasure ami

With a few remarks, congratulating the Society on the completion of
another year of prosperity and mutual good wall, Mr. Gilbert declared
the fourth annual meeting adjourned.

The following Fellows were in attendance at the meeting

F. W. Claypole.

J. S. DlLLEK.
E. T. DUMBLE.

B. K. Emebson.
H. L. Fairchild.

G. K. Gilbert.

C. W. Hall.

('. Willard Hayes.
Alphels Hyatt.
Daniel W. LangdoN, -Ik
W -I McGee.

Total attendance. 23.

Thomas F. Moses.
Peter Xeff.
William H. Pettee.
I.e. Russell.
Will H. Sherzer.
John ( !. Smock.
J. W. Spencer.
E. 0. Ulrich.
I. C. White.
Arthur Winslow.
J. F. Wolff.
G. Frederick Wright.

Hjalmar Lundbohm, of the Geological Survey of Sweden, also attended

the meeting.

LIST OF

OFFICERS AND FELLOWS OF THE GEOLOGICAL SOCIETY

OF AMERICA.

OFFICERS FOR 1892.

President.
G. K. Gilbert, Washington, I). ('.

I ice-Presidents.

Sir .1. William Dawson, Monteal, Canada.
T. ( '. Chamberlin, Madison. Wis.

Secretary.
II. L. Fairchild, Rochester, XVw York.

Treasurer.
I.e. White, Morgantown, W. Va.

( buncillors.

Class of 1894.

Henry S. Williams. Ithaca, New York.
X. II. Winchell, Ann Arbor. Mich.

Class of 1893/

George M. Dawson. Ottawa. Canada.
John ( '. Branner, Little Rock, Arkansas.

Class of L892.

E. W. < 'layi'olk. Akron, < >hio.

( !has. 1 1. 1 1 [tchcock, Hanover, X. II.

Editor.
W .1 McGee, Washington, D. C.

(5231

FELLOWS, JULY 1. 1891.

* Indicates Original Fellow sec article TIT of Constitution'),
f Indicates decedent.

Frank Dawson Adams, Montreal, Canada ; Lecturer on Geology at McGill College.

December, 1889.
Victor C. Alderson, 6721 Honore St., Englewood, Ills. December, 1889.
Truman H. Aldrich, M. E., 92 Southern Ave., Cincinnati, Ohio. May, 1889.
Henry M. Ami, A. M., Geological Survey < >ffice, < >ttawa, Canada ; Assistant Paleon-
tologist on Geological and Natural History Survey < »f ( anada. I tecember, 1889.
*t Charles A. Ashburner, M. S., C. E. (Died December 24, L889.
George H. Barton, B. S., Boston, Mass.; Instructor in Geology in Massachusetts

Institute of Technology. August, L890.
William S. Bayley, Ph. D., Waterville, Maine: Professor of Geology in Colby

University. December. 1888.
* George F. Becker, Ph. D., Washington, D. C. ; U. S. Geological Survey.
Charles E. Beecher, Ph. D., Yale University, New Haven, Conn. May, 1889.
Robert Bell, C. E., M. D., LL. D., Ottawa. Canada: Assistant Director of the

Geological and Natural History Survey of Canada. May, 1889.
Albert S. Bickmore, Ph. D.. American Museum of Natural History, 77th St. and

Eighth Ave., N. Y. City ; Curator of Anthropology in the American Museum of

Natural History. December, 1889.
William P. Blake, New Haven, Conn. August, 1891.
Stephen Bowers, A. M.. Ph. D.. Mineralogical and Geological Survey of California.

Ventura, California, May, 1889.
Amos Bowman, Anacortes, Skagit Co., Wash. State. May, 1889.
Ezra Brainerd, LL. D.. Middlebury, Vermont; President of Middlebury College.

December, 1889.
*John C. Branner. Ph. D., Menlo Park, Cal. ; Professor of Geology in Leland Stan-
ford Jr. University: State Geologist of Arkansas.
Oakland C. Broaduead, Columbia, Mo.; Professor of Geology in the University

of Missouri.
"Walter A. Brownell, Ph. D.. 905 University Ave., Syracuse, N. Y.
■S\mi"ei. Calvin, Iowa City, Iowa ; Professor of Geology and Zoology in the State

University of Iowa.
Henry Donald Campbell, Ph. D., Lexington, Va. ; Professor of Geology and

Biology in Washington and Lee University. May, 1889.
Franklin R. Carpenter, Ph. D., Rapid City, South Dakota ; Professor of Geology

in Dakota School of Mines. May, 1889.
Robert Chalmers, Geological Survey Office, Ottawa, Canada ; Field Geologist on

Geological and Natural History Survey of Canada. May, 1889.
":fT. C. Chamberlin, LL. D., Madison, Wis.; President University of Wisconsin.
Henry M. Chance, M. D., Philadelphia. Pa.; Geologist and Mining Engineer.

August, 1890.
*fJ. H. Chapin, Ph. D.. Meriden. Conn, i Died March 14. 1X92.)

(524)

LIST OF FELLOWS. 525

Clarence Raymond Claghorn, B. S., M. E., 204 Walnut Place, Philadelphia, Pa.
August, 1891.

* William B. Clark, Ph. D., Baltimore, Md.; Instructor in Geology in Johns

Hopkins University.

* Edward W. Claypole, D. Sc., Akron, 0. ; Professor of Geology in Buchtel College.
Aaron H. Cole, A. M., Englewood, 111. December, 1889.

* John Collett, A. M., Ph. D., Indianapolis, Ind. ; lately State Geologist.

* Theodore B. Comstock, Tucson, Ariz. ; Directer Arizona School of Klines,
t George H. Cook, Ph. D., LL. D. (Died September 22, 1889.)

* Edward D. Cope, Ph.D., 2102 Pine St.. Philadelphia; Professor of Geology in

the University of Pennsylvania.

* Francis W. Cragin, B. S., Topeka, Kansas; Professor of Geology and Natural

History in Washburne College.
Albert R. ('randall, A. M., Lexington, Kentucky; Professor of Geology in
Agricultural and .Mechanical College of Kentucky.

* William 0. Crosby, B. S., Boston Society of Natural History, Boston, Mass. ;

Assistant Professor of Mineralogy and Lithology in Massachusetts Institute of
Technology.
Charles Whitman Cross, Ph. D., U. S. Geological Survey, Washington, D. C.
May, 1889.

* Malcolm H. Crump, Bowling Green, Kentucky; Professor of Natural Science in

Ogden College.
I i \rry E. Culver, A. M., Beloit, Wis.

-Henry P. Cushing, M. S., 786 Prospect St., Cleveland, Ohio.
T. Nelson Dale, Newport, R. I.; Assistant Geologist, U. S. Geological Survey.

December, 1890.

* James D. Dana. LL. D., New Haven, Conn.; Professor of Geology in Yale Uni-

versity.

* Nelson H. Darton, United States Geological Survey, Washington, D. C.
■William M. Davis, Cambridge, Mass.; Professor of Physical (geography in

Harvard University.

George M. Dawson, D. Sc, A. R. S. M., Geological Survey Office, Ottawa, Can. ; As-
sistant Director Of Geological and Natural History Survey of Canada. May, L889.

Sir J. William Dawson, LL. D., McGill Gollege, Montreal, Canada ; Principal of
McGill University. May, 1889.

David T. Day, A. B.,Ph.D. TJ. S. Geological Survey, Washington, D. C. Aug., L891.

Frederick P. Dewey, Ph. B., 621 F St. X. W., Washington, D. C. May, L889.

Orville A. Derby, M. S., Sao Paulo, Brazil; Dire -tor of the Geographical and
Geological Survey ofthe Province of Sao Paulo, Brazil. December, L890.

* Joseph S. Diller, B. s„ United States Geological Survey, Washington, D. ('.
Edward V. d'Invilliers, E. M., 711 Walnul St., Philadelphia, Pa. December, 1888

I'.nwis T. Di vible, Austin, Texas ; State Geologist.
Maj. Clarence E. Dutton, Ordnance Department, U. S. A., San Antonio, Texas.
August, I sin.
Willi wi B. Dwight, M. A., Ph. B., Poughkeepsie, V Y.: Professor of Natural

I [istory in Vassar ( lollege.
i rEORGE II. Eldridge, A.. B., United States < reological Survey, Washington, D. C.
Robert W. Ells, LL. D., Geological Survey Office, Ottawa, Canada ; Field Geolo
. gist on Geological and Natural History Survey of Canada. December, 1888

l,\ \ I Bum.. Oi oi 3o< . \>i . Vol. 3, 1801

526 PROCEEDINGS OF COLUMBUS MEETING.

* Benjamin K. Emerson, Ph. D., Amherst, Mass. ; Professor in Amherst College.
Samuel F. Emmons. A. M., E. M., U. S. Geological Survey. Washington, D. C.

John Eyerman, Easton, Pa. August, 1891.

♦Herman L. Fairchild, B. S., Rochester, X. Y. ; Professor of Geology and Natural

History in University of Rochester.
J. C. Fales, Danville, Kentucky ; Professor in Centre College, December, 1888.
Eugene Rudolph Faribault, C. E., Geological Survey Office, Ottawa, Canada.

August, 1891.
P. J. Farnsworth, M. D., Clinton. Iowa ; Professor in the State University of Iowa.

May, 1889.
Moritz Fischer, 721 Cambridge St., Cambridge, Mass. May, 1889.
♦Albert E. Foote, M. D., 4116 Elm Ave. Philadelphia, Pa.
William M. Fontaine, A. M.. University of Virginia, Va. ; Professor of Natural

History and Geology in University of Virginia. December, 1888.
*P. Max Foshay, M. S., M. D., 3 Park Ave., Rochester, N. Y.

* Persifor Frazer, D. Sc, 1042 Drexel Building, Philadelphia. Pa.; Professor of

Chemistry in Franklin Institute.

* Homer T. Fuller, Ph. D., Worcester, Mass. ; Professor of < leology in Worcester

Polytechnic Institute.
Henry Gannett, S. B.. A. Met. B.. U. S. Geological Survey. Washington, D. C.
December, 1891.

* Grove K. Gilbert, A. M.. United States Geological Survey, Washington, D. ('.
Adams ( .'. Gill, A. B., Northampton, Mass. December, 1888.

N. J. Giroex, C. E., Geological Survey Office, Ottawa, Canada; Assistant Field

< reologist, Geological and Natural History Survey of Canada. May, L889.
Ulv. s. Grant, B. S., Johns Hopkins University, Baltimore, Md.

* George B. Grinnell, Ph. D., 318 Broadway, New York city.
":;~ William F. E. Gurley, Danville, Illinois.

Arnold Hague, Ph. B., U. S. Geological Survey, Washington, D. C. May, 1889.

-Christopher W. Hall, A. M., 803 University Ave., Minneapolis, Minn. ; Pro-
fessor of Geology and Mineralogy in University of Minnesota.

♦James Hall, LL. D., State Hall, Albany, N. Y. : State Geologist and Director of
the State Museum.

Henry G. Hanks, 1124 Greenwich St., San Francisco, Cal. ; lately State Mineralo-
gist. December, 1888.

John B. Hastings, M. E., Boise City, Idaho. May, 1889.

♦Erasmus Haworth, Ph. D., Oskaloosa, Iowa; Professor of Natural Sciences in
Penn College.

* Robert Hay, Box 562, Junction City, Kansas; Geologist, U. S. Department of

Agriculture.
C. Willard Hayes, Ph. D., U. S. Geological Survey, Washington, D. C. May, 18S9.
•;" Angelo Heilprin, Academy of Natural Sciences. Philadelphia, Pa.; Professor of

Paleontology in the Academy of Natural Sciences.
Clarence L. Herrick, M. S., 324 Hamilton Ave., North Side, Cincinnati, Ohio;

Professor of Geology and Biology in the University of Cincinnati. May. 1889.
-Lewis E. Hicks, Lincoln, Nebraska.

* Eugene W. Hilgard, Ph. D., LL. D., Berkeley. Cal. ; Professor of Agriculture in

University of California.
Frank A. Hill, 208 S. Centre St., Pottsville, Pa. : Geologist in Charge of Anthra-
cite District, Second Geological Survey of Pennsylvania. May, 1889.

LIST OF FELLOWS. 527

* Robert T. Hill, B. S., U. S. Geological Survey, Washington, D. C.

■Charles H. Hitchcock, Ph. D., Hanover, N. H. ; Professor of Geology in Dart-
mouth College.

William Herbert Hobbs, B. Sc, Ph. D., .Madison, Wis. ; Assistant Professor of
Mineralogy in the University of Wisconsin. August, 1891.

* Levi Holbrook, A. M., P. 0. Box 536, New York city.

* Joseph A. Holmes, Raleigh, North Carolina; State Geologist and Professor of

Geology in University of North Carolina.
Mary E. Holmes, Ph. D., 201 S. First St., Rockford, Illinois. May, 1889.
t David Hoxeyman, D. C. L. (Died October 17, 1889.)

* Jedediaii Hotchkiss, 346 E. Beverly St., Staunton, Virginia.

* Edmund O. Hovey, Ph. D., Waterbury, Conn.

* Horace C. Hovey, D. D., Middletown, Conn.

* Edwin E. Howell, A. M., 537 15th St. N. W., Washington, D. C.

t Thomas Sterry Hunt, D. Sc, LL. D., Park Avenue Hotel, New York city. De-
cember, 1889. (Died February, 1892.)

;- Alpheis Hyatt, B. S., Bost. Soc. of Nat. Hist., Boston, Mass. ; Curator of Boston
Society of Natural History.

Joseph P. Iddings, Ph. B., U. S. Geological Survey, Washington, D. C. May, L889.

A. Wendell Jackson, Ph. B., Berkeley, Cal. ; Professor of Mineralogy, Petrog-
raphy and Economic Ceology in University of California. December, 1888.

Thomas M. Jackson, C. E., Morgantown, W. Va. ; Professor of Civil and Mining
Engineering in West Virginia University. May, 1889.

* Joseph F. James, M. S., Department of Agriculture, Washington, D. C.
Walter Proctor Jexney, E. M., Ph. D., United States Geological Survey, Wash-
ington, D. C. August, 1891.

* Lawrence C. Johnson, United States Geological Survey, Meridian, Miss.

* Willard D. Johnson, United States Geological Survey, Berkeley, Cal.

Alexis A. Julien, Ph.D., Columbia College, New York city; Instructor in Co-
lumbia College. May, 1889.
Edmund Jussen, Ph. D., Temple, Carroll ( !o., < ra. December, 1890.
Arthur Keith, A. M., l\ S. ( Geological Survey, Washington, D. C. May, 1889.
*Jauks F. Kemp, A. B., E. M., Columbia College, New York city ; Adjunct Professor

of Geology.
( Iharles R. Keyes, A. M., Assistant State Geologist, Des Moines, la. August, 1890.
James P. Kimball, Ph. I>., Washington, D. ( '. August, L891.
Clarence King, 18 Wall St., New York city; lately Director of the F. s. Geological

Survey. May, L889.
Frank II. Knowlton, M. S., Washington, D.C.; Assistant Paleontologist F. s. I }eo-

logical Survey. May, L889.
< George l'. Ki nz, 402 Garden St., Hoboken, N. J.
R. D. Lacoe, Pittston, Pa. December, L889.

George Edgab Ladd, A. B., A. M., Jefferson City, Mo.; Assistant Geologist, Mis-
souri Geological Survey. August, L891.
.1. c. K. Laflamme, M. A., D. D.. Quebec, Canada; Professor of Mineralogy and

Geology in University Laval, Quebec. August, L890.
Lawrence M. Lambe, Ottawa, Canada ; Artist and Assistant in Paleontology and

Geological Survey of Canada. August, L890.
Alfred I '. Lane, Ph. D.. Houghton, Michigan ; Assistanl on < teological >ur\cy of

Michigan. December, L889.

528 PROCEEDINGS OF COLUMBUS MEETING.

Daniel W. Langdon, Jr., A. B., University Club, Cincinnati, Ohio; Geologist of
Chesapeake and Ohio Railroad Company. December, 1889.

Andrew C. Lawson, Ph. D., Berkeley, Cal. ; Assistant Professor of Geology in the
University of California. May, 1889.

* Joseph Le Coxte, M. D., LL. D., Berkeley, Cal.; Professor of Geology in the

University of California.

* J. Peter Lesley, LL. D., 1098 Clinton St., Philadelphia, Pa. ; State Geologist.
Frank Leverett, B. S., 4103 Grand Boulevard, Chicago, 111. August, 1890.
Josua Lindaiil, Ph. D., Springfield, Ills.; State Geologist. August, 1890.
Waldemae Lindgren, U. S. Geological Survey, Washington, D. C. August, 1890.
Robert H. Loughridge, Ph. D., Berkeley. Cal. ; Assistant Professor of Agricultural

Chemistry in University of California. May, 1889.
Thomas H. McBride, Iowa City, Iowa ; Professor of Botany in the State University

of Iowa. May, 1889.
Henry McCalley, A. M., C. E., University, Tuscaloosa County, Ala.; Assistant on

Geological Survey of Alabama. May, 1889.
Richard G. McConxell, A. B., Geological Survey Office, Ottawa, Canada ; Field

Geologist on Geological and Natural History Survey of Canada. May, 1889.
James Riemax M \< faki.am:. A. B., Pittsburg, Pa. August, 1891.
*W J McGee, United States Geological Survey, Washington, D. C.
William McInnes, A. B., Geological Survey Office, Ottawa, Canada; Assistant

Field Geologist, Geological and Natural History Survey of Canada. May, 1889.
Peter McKellar, Fort William, Canada. August, 1S90.
Oliver Marcy, LL. D., Evanston, Cook Co., Illinois; Professor of Natural History

in Northwestern University. May, 1889.
Othxiel C. Mabsh, Ph. D., LL. I)., New Haven, Conn. ; Professor of Paleontology

in Yale College. May, 1889.
P. H. Mell, M. E., Ph. D., Auburn, Ala. : Professor of Geology and Natural History

in the State Polytechnic Institute. December, 1888.

* Frederick J. H. Merrill, Ph. D., State Museum, Albany, N. Y. ; Assistant State

Geologist and Assistant Director of State Museum.

George P. Merrill, M. S., U. S. National Museum, Washington, D. C. ; Curator of
Department of Lithology and Physical Geology. December, 1888.

James E. Mills, B. S., Quincy, Plumas Co., Cal. December, 1888.

*Albro D. Morrill, A. M., M. S., Clinton, N. Y. ; Professor of Geology in Hamilton
College.

Thomas F. M< >ses, M. D., Urbana, Ohio ; President of Urbana University. May, 1889.

■^ Frank L. Nason, A. B., 5 Union St., New Brunswick, N. J.; Assistant on Geo-
logical Survey of New Jersey.

* Henry B. Nason, Ph. D., M. D., LL. D., Troy. N. Y. ; Professor of Chemistry and

Natural Science in Rensselaer Polytechnic Institute.

* Peter Neff, A. M., 361 Russell Ave.. Cleveland, Ohio.

* Jonx S. Newberry, M. D., LL. D., Columbia College, New York city ; Professor

of Geology and Paleontology in Columbia College.
Frederick H. Newell, B. S., U. S. Geological Survey, Washington, D. C. May, 1889.
William H. Niles, Ph. B., M. A., Cambridge, Mass. August, 1891.

* Edward Ortox, Ph. D., LL. D., Columbus. Ohio : State Geologist and Profes.-or

of Geology in the State University.

* Amos O. Osborx, Waterville, Oneida Co., N. Y.
*t Richard .Owex, LL. D. (Died March 24, 1890.)

LIST OY FELLOWS. 529

* Horace B. Patton, Ph. D., New Brunswick, X. J.; Assistant Professor of Geology

and Mineralogy in Rutgers College.
Richard A. F. Penrose, Jr., Ph. D., 1331 Spruce St., Philadelphia, Pa. May, 1889.
Joseph H. Perry, 170 Highland St., Worcester, Mass. December, 1888.

* William H. Pettee, A. M., Ann Arbor, Mich.; Professor of Mineralogy, Eco-

nomical Geology, and Mining Engineering in Michigan University.
:J Franklin Platt, 1319 Walnut St., Phladelphia, Pa.

* Julius Pohlman, M. D., University of Buffalo, Buffalo, X. Y.

William B. Totter, A. M., E. M., St. Louis, Mo. ; Professor of Mining and Metal-
lurgy in Washington University. August, 1890.

* John W. Powell, Director of U. S. Geological Survey, Washington, D. C.

* John R. Procter, Frankfort, Ivy. ; State Geologist.

* Charles S. Prosser, M. S., U. S. National Museum. Washington, D. C.

* Raphael Pumpellv, U. S. Geological Survey, Newport, R. I.

William North Rue, A. M., Ph. D., LL. D., Middletown, Conn.; Professor of
Geology in Wesleyan University. August, 1890.

* Eugene X. S. Ringueberg, M. D., Lockport, N. Y.

.Charles W. Rolpe, M. S., Urbana, Champaign Co., Illinois; Professor of Geology
in University of Illinois. May, 1889.

* Israel C. Russell, M. S., Ann Arbor, Mich. ; Professor of Geology in University

of Michigan.

* James M. Safpord, M. I)., LL. D., Nashville, Tenn. ; State Geologist; Professor

in Vanderbilt University.
< >restes H. St. John, Topeka, Kansas. May, 1889.

* Rollin D. Salisbury, A. M., Madison, Wis. ; Professor of General and Geographic

Geology in University of Wisconsin.

-Charles Schaepfer, M. D., 1309 Arch St., Philadelphia, Pa.

Henry M. Seely, M. D., Middlebury, Vt. ; Professor of Geology in Middlebury Col-
lege. May, 1889.

Alfred R. C. Selwyn, C. M. G., LL. D., Ottawa, Canada; Director of Geological
and Natural History Survey of Canada. December, 1889.

'' Nathaniel S. Shaler, LL. T>., Cambridge, Mass.; Professor of Geology in Har-
vard University.

Will H. Sherzer, M.S., Ann Arbor, Mich. ; Instructor in Geology and Paleon-
tology, University of Michigan. December, 1890.

*FREDERICK W. SlMONDS, Ph. !>., Austin, Texas ; Professor of Geology in Univer-
sity of Texas.

*Er/GENE A. Smith, I'h. !>.. University, Tuscaloosa Co., Ala.; State (Jeologisl and
Professor of Chemistry and Geology in University of Alabama.

* John C. Smock, Ph. D., Trenton, X..!.; State Geologist.

.1. W. Spencer, A. M., I'h. D., Atlanta, Georgia; State Geologist.
Timothy Willi \m Stanton, B. S., IT. S. Geological Survey, Washington, l>. ( '. ;
Assistant Paleontologist U.S. Geological Survey. August, 1891.
John J.Stevenson, Ph. !>., CTniversity of the City of New York; Professor of
' leology in the University of the City of New York.
George C. Swallow, M. I>., LL. D., Helena, Montana ; State Geologist ; latelyState

Geologisl of Missouri, and also of Kansas. December, 1889.
Ralph S. Take, Cornell University, [-thaca, N. V. August, L890.
Maurice Thompson, Crawfordsville, End.; Lately State Geologist. May. 1889.
\-\ Scott Tiffany, 901 West Fifth St., Davenport, Lowa.

530 PROCEEDINGS OF COLUMBUS MEETING.

* James E. Todd, A. M., Tabor, Iowa ; Professor of Natural .Sciences, Tabor College.

* Henry W. Turner, U. S. Geological Survey, Washington, D. C.

Joseph B. Tyrrell, M. A., B. Sc, Geological Survey Office, Ottawa, Canada ; Geol-
ogist on the Canadian Geological Survey. May, 1889.

* Edward O. Ulricii, A. M., Newport, Ky.

* Warren Upham, A. B., 36 Newbury St., Somerville, Mass.; Assistant on the

U. S. Geological Survey.

* Charles R. Van Hise, M. S., Madison, Wis. ; Professor of Mineralogy and

Petrography in Wisconsin University ; Geologist IT. S. Geological Survey.

* Anthony W. Vogdes, Alcatraz Island, San Francisco, Cal. ; Captain Fifth Artillery,

U. S. Army.
Charles Wachsmuth, M. D., Burlington, Iowa. May, 1889.
*Marshman E. Wadsworth, Ph.D., Houghton, Mich. ; State Geologist; Director

of Michigan Mining School.

* Charles D. Walcott, IT. S. National Museum, Washington, D. C. ; Paleontolo-

gist U. S. Geological Survey.

Lester F. Ward, A. M., U. S. Geological Survey, Washington, D. C. ; Paleontolo-
gist U. S. Geological Survey. May, 1889.

Walter H. Weed, M. E., IT. S. Geological Survey, Washington, D. C. May, 1889.

David White, IT. S. National Museum, Washington, D. C. ; Assistant Paleontolo-
gist U. S. Geological Survey, Washington, D. C. May, 1889.

* Israel C.White, Ph. D., Morgantown, W. Va. ; Professor of Geology in West

Virginia University.

* Charles A. White, M. D., U. S. National Museum, Washington, D. C. ; Paleon-

tologist U. S. Geological Survey.

* Robert P. Whitfield, Ph. D., American Museum of Natural History, 77th St.

and Eighth Ave., New York city ; Curator of Geology and Paleontology.

* Edward H.Williams, Jr., A. G, E. M., 117 Church St., Bethlehem, Pa.; Pro-

fessor of Mining Engineering and Geology in Lehigh University.

* George H.Williams, Ph. D., Johns Hopkins. University, Baltimore, Md. ; Pro-

fessor of Inorganic Geology in Johns Hopkins University.

* Henry S. Williams, Ph. D., New Haven, Ct, ; Professor of Geology and Paleon-

tology in Yale University.
*t J. Francis Williams, Ph. D., Salem, N. Y. (Died November 9, 1891.)

* Samuel G. Williams, Ph. D., Ithaca, N. Y. ; Professor in Cornell University.
Bailey Willis, U. S. Geological Survey, Washington, D. C. December, 1889.
*t Alexander Winchell, LL. D. (Died February 19, 1891.)

* Horace Vaughn Winchell, 10 State St., Minneapolis, Minn.; Assistant on Geo-

logical Survey of Minnesota.

* Newton H. Winchell, A. M., Minneapolis, Minn. ; State Geologist; Professor in

University of Minnesota.

* Arthur Winslow, B. S., Jefferson City, Mo.; State Geologist.

John E. Wolff, Ph. D., Harvard University, Cambridge, Mass. ; Instructor in

Petrography, I Iarvard University. December, 1889.
Robert Simpson Woodward,- C. E., U. S. Coast and Geodetic Survey, Washington,

D. C. May, 1889.
*G. Frederick Wright, D. D., Oberlin, Ohio: Professor in Oberlin Theological

Seminary.
Lorenzo G. Yates, M. D., Santa Barbara, Cal. Pecember, 1889.

INDEX TO VOLUME :■}.

Page

Adirondack^, Pleistocene shores on the 4xs

Acassiz, A., Cited on echinoids 104, 1115

Ai. lb un, Asphalt in 188

— , Middleton formation of 511

Alaska, Geology of 495, 496

— , Glaciers of L39

Alectryonia, New species of 4(14

Algonkian rocks of Minnesota 335

, Relations of Silurian to 155

Algonquin lake 484

A i.ii \, Colonel, Cited on natural gas 207

Ai.i.kn, J., Exploration by, cited 333

Allport. Samuel, Cited on thermometamor-

phism 16

American Association fur Tin: Advancement
of Science, Reprint from proceedings

of the 215

American Manufacturer, Reprint from the. 'Jul

Ami, H. M., Cited on Seolithus 41

Ammonites colfaxii, Significance of 43U

Amurcaceous, Definition of term 132

Analysis of coal 317

eleolite-syenite 242

hornblende-syenite 24!i

magnesian limestone 348

Potsdam sandstone 339

Trenton limestone 358

Andrews, B. B., Cited on the origin of petro-
leum 193

Anomia, New species of. 401

Anticlinal structure of northern California. 388

— theory, Development of the. 193

(The criticisms of the) of natural gas;

I. C. White 215

(The) of natural gas; I. C. White 204

Am E8TBS californiensis, Naming of species... 398

Aechean of the Sierra Nevada. 424

Aiu/.ona, Triassic of 25

Arkansas, Eleolite-syenite of 83

— , Iron ores of 44

Arlington beds, Description of 375

Akmington, Section at 321

Arnioi eras woodhulli, Naming of species 411

Artesian wells, A source of supply for 124

Ashburner, C. A , Cited on < California geology. :s7o
—, Criticism of-" anticlinal theory" by... 206,215

Astraspis desiderata, Founding of species 166

\ i ci mm; Committee, Report or 470

Ai\ Vases sandstone, Definition of 295

Baldwin, Prentiss, Collection by 305

Barrois, in.. Cited on thermometamor-

pliism 16

Bashford, , Record of address by 165

Bassett„Mari E, Analysis by .' :;is

Bayle, Emile, cited on He Jura of South

Am 109

Bayi by, u . S.; Eleolite syenite of Litchfield,

M ■ and Hawes' hornblende-syenite

from Red Hill. New Hampshire. '. 231

— , Record of discussion by 84

— , Title of paper by ,i i

Bear creek mine's. :;■_'*

Bei k T. R , Cited on thermometamorphism. 16
Becker, Q. !•'.. Cited on the Cretaceous of

California \-i:<, 138

deformation of the Sierra Nevada.... 1 1 * •

post Imi--ic epeirogeny 382

Page
Becker, G. P., Cited on the geology ofCali-

I fornia 414

vuleanism in California ::'.il

Beech, W. A., Analysis by 358

Belemnites, Development of the 62

— , New species of 405

Bell, Robert, Cited on Pleistocene submer-
gence 509

Belt butte, Section of 306

— creek mines 318

, Section of 307

Belt, Thomas, Cited on Pleistocene submer-
gence 510

Bibliography of J. Francis Williams 458

Bicknell sandstone, Description of 373, 4titj

— tuff, Description of 407

Big Bone cave, Fossils from 121

" Big Injun" sand, oil from the 188

Billings, E., Cited on Cambrian fossils.. 51G

Paleozoic corals 256

Seolithus ::7

Biological Society of Washington, Notice

read before the I .v.

Blai k Eagle falls, Section at :;il

"Black Earth" (The) of the steppes of

southern Russia; A. N. Krassnof 68

Blake, W. P., Cited on faulting in the Sierra

Nevada 438

— ■ granite in the Sierra Nevada 424

Blanchard, Miss M. L., Analysis by 358

Blue limestone, Description of 360

Bohemia, Fossil coral from 275

Bones, Fossil, from Tennessee 121

Boonville, Pleistocene terraces at 491

Boring (A deep) in the Pleistocene near

Akron, Ohio; E. W. Claypole 150

Bowman, Amos, Cited on the Sierra Nevada... 416
Brackett, R. N., Reference to, as joint au-
thor 457

Brainerd, Ezra, Acknowledgment to 38

, Quoted on Seolithus . 42

Branner, J. C, Reference to, as state geol-
ogist .' 457

I Ik a v\ is, A re i ste. Cited on changes of level. 65
Brewer, W. H., Cited on California geology. 370

Bkidoes, Natural, of Florida "... 132

Broadhead, '■. C, Acknowledgments to 272

— . cited on deformation 110, 112. ill

Kimlcrhook beds 289

— , Discussion of "black earth" by 80

Bbogger, W. C, cited on eleolite-syenite 237

Brongniart, I... Cited on Triassic plants 24

Burr limestone, Description of 360

Bulletin. Cost of 469

, Distribution of \i~

I'.i \.;i by, Sir i maim is .1. I-'., i lited on Trias-
sic plants j I

Bi &LINGTON limestone, Definition of 292

. Section ai 285

Bi fuuLL, II. II.. Acknow ledgments to 31 I

Buvionier, L, Cited on the genus Opis 403

By-Laws, Proposed amendment to 370

Cadell, ii. M.. Title of paper by ..

i mii orni \. i lienegas or

— , Geology of Taj lorville

— , Jura and Trias at T:iy iurville..

Peculiar deposits in

124

l 13

(531)

532

BILL. GEOL. SOC. AM.

Page
California. Rocks of the Sierra Nevada in.. 413
Calvin, Samuel, Cited on [owa stratigraphy. 288

Camarella bed, Description of 364

Cambrian formations of Minnesota :'>-_'. 1> I

— rocks of the Green mountains 514

Canada, Drift of. L42

— , Fossil coral from 267

— , Glacial lakes of 485

Canyon city. Paleozoic fossils from 153

Carboniferous faunas 102

— (Permian) fossils 217

— of Alaska 405

California 3?2

Missouri. 109

— — Montana 308

South America 14

the East Indies 15

— rocks, Oil from 188

, Section of. 283

Carel, H. C, Analysis by 348

Carll, J. F., Cited on natural gas 213

— , Criticisms of ''anticlinal theory" by 215

Carnegie, Andrew, Cited on natural gas 204

Carpenter, F. R., Analysis by 54

— , Cited on Silurian fossils 163

Carver, Jonathan, Reference to travels of... 333
Chamberlain, T. C, Cited on distribution of

bowlders 233

drift 135, 144

extra-morainic drift 174

glacial episodes 181

kames 145

Paleozoic unconformities 353

rock structure 343

Scolithus 40

supposed Huroniau rocks 335

— Tertiary gravels 183

the driftless area of southeastern

Minnesota 332

— , Election of, as Yi' e-Pi.-sident 454

— , Finding of Saint Peter fossils by 352

— , Record of discussion by 68, 81. 134

— , Title of paper by 133

Champlain (The) submergence ; Warren Up-

ham 508

— valley. Glacial lakes of the 486

Chance, H. M., Cited on natural gas 208

— , Criticisms of " anticlinal theory" by 215

Chanfv. L. W., Cited on Cryplozooa 244

Channels over divides not evidence per se

of glacial lakes ; J. W. Spencer 491

Chapin, F. H., Donation of photographs by... 477

Chapman. E. J., Cited on glacial lakes 484

Chapple, C. 8., Analysis by 348

Chattahoochee embayment >:The); L. C.

Johnson 128

Chemnitzia, New species of 407

Chernozem, Definition of. 68

• 'hester beds, Definition of. 295

— , Section at 287

Chonophyllum greeni, Founding of species... 275

— pseudohelianthoides, Founding of species.. 275

— (A revision and monograph of the genus) ;

W. H. Sherzer 253

I'iihi i-eau limestone. Definition of 288

Cidaris, New species of. 402

Cienagas, Definition of 124

— (The) of southern California: E. W. Hil-

gard 124

< i\ [nnati group, Description of 365

Clark, \V.. Title of paper by 500

Clark, W. B., Cited on echinoids 103

.Clarke, F. W , Acknowledgments to 233

— , Analysis of eleolite-syenite by 234

— , Cited on eleolite-syenite 236

Claremont. Rocks of 422

Claypolb, E. W.; A Deep Boring in the Ple-
istocene near Akron, Ohio 150

— , Cited on glacial lakes 484

Megalonyx 122

Silurian fish remains 165

Page
Ci.avpole, E. W.; Discussion of fossil plants

from Texas by 459

isostasy by 503

— Silurian fish remains by 168

— . Record of discussion by.... 23, 41. 133, 459, WO

— , Title of paper by 500, 504

Clough, R. <>.. Acknowledgments to 232

Coal, Analyses of 317

— fields, .Montana 301

Coal Measures of Missouri 109

the Mississippi valley 297

Coal series of Texas, Description of the 225

Cocker, II. I;.. Acknowledgments to :;14

Cole, A. EL; Palaenater euekaris, Hall 512

< Colorado, Silurian vertebrates from 153

— , Triassic of. 25

Columbia formation, Continental oscillations

represented by 502

in Texas 230,483

Columbian University, Meeting in 2

Columbus meeting. Proceedings of 453

, Register of "22

Committee on photographs, Report of 470

— , Report of auditing 470

Comstock.T.B .Cited on Cretaceous of Texas. 224

— , Title of paper by 124

1 onnei tk it. Triassic of. 25

Conophylltjm, Relations of 267

Constitution, Failure of proposed amend-
ment to. 455

Convfvi Hilt. Section at 226

Cook, G. H , Cited on Yellow gravel 182

— , Reference to work of 173

Cope, E. D., Cited on deformation in
Texas 94

— geology of Texas 230

Permian fossils 459

— , Discussion of Silurian fish remains by... 168

— , Record of discussion by 14, 23,83, 123

Coouani", Henri, Cited on the Jura of North

America 409

Corals, Paleozoic 253

Correlation of East Indian formations 15

South American deposits 14

the Jura-Trias 23

Cotteau. Gistave, Cited on Echinoids 103

Council, Report of the 400

Cow creek. Section on 223

Crandall, A. R., Cited on trap dikes 50

Crazy mountains (The geology of the), Mon-
tana: J. E. Wolff..... 445

Cbetai 1 1 • ' ds, Early 61

— deposits of Texas 85, -->>

— echinoids 103

— of California 125

Montana 310,446

Nebraska 52

South America 13

the plains 519

Crosby, W. O., Cited on hornblende-syenite. 24:;

Cross, J. G.. Analysis by 348

Cross, Whitman, Cited on volcanic' rocks 17

Crosskey, EL W„ Cited on altitudes 506

Crossman, J. H., Dedication of species to 411

Ctenostreon, New species of. 402$ l11".

Culver, G. E.. Collaboration by 51

Cummins, W. F., Collection by 217

Curtice cliff, Naming of 396

( Iurtice, Cooper, Cited on California geologj

— . < lollections by 396

— , Dedication of species to 408

Curtiss, Ii. R., < lited on natural gas 209

Coshing. II. I'.. Cited on Alaskan glaciers.... 5o7

— , Publication of photograph by 478

— , Record of discussion by 56

Cyathophyllum, Discussion of genus 279

Dakota, Geology of 519

— rocks in Montana 310

Dale, T. N.. cited on mount Greylock 461

INDEX TO VOL. 3.

533

Page
Dale, T. N. ; On the structure and age of
the Stockbridge limestone in the Ver-
mont valley 514

— , Quotations from, on rocks of tin/at Har-
rington 462

Dall, w. H., Identification of species by 496

Dames, Wilhelm, < ited on Scutithus 40

Dana, J. D., Cited on Chonophyttum 281

climate ?:;

drift 135

geology of Massachusetts 460

Scolithus 38

■ Triassic deposits 25

Wing's work 518

Daonella bed. Description of 397

— tenuistriata, Naming of species 197

Davis, W. J., Cited on Paleozoic corals 267

Davis, W. M., Cited on dip plains 85

Montana stratigraphy 303

Pleistocene terraces 487

— , Explanation of photographs by... 171, 175,476

-, On committee on photographs 470

Dawson, G. M., Cited on bowlders 145

drift 142

■ — post-Triassic epeirogeny 382

the Kootanie formation 322

Trias of British Columbia -".7!)

Vulcanism in California 37<i

— , Photographs by 481

Dawson, Sir J. William, Election of as vice-
president 454

Deformation of California rocks 378

southeastern United States 502

— in Missouri 110

Texas and New Mexico 85

■ the Green mountains 516

Siena Nevada 416

— , Pleistocene 65, 508

Del Rio, Geology aboui 220

Denton, A. J., Collection of fossils by 121

Deposition of Missouri Coal Measures 109

Derby, 0. A., Title oi paper by 133

Desor, E., Cited on echinoids 105

Devonian fauna oi Bolivia 13

fossil 512

— rocks of Minnesota 332, 367

Dictyorhabdus prisons. Founding of genus

and species 165

I IlKES, San 1 Is tone 50

I oi 1 in, J. S.. Acknowledgments to 233, 396

— , Cited on California structure 383

geology of Lassen peak 415

hornblende-syenite 243

— sandstone dikes 51

sodalite 210

— , Collections by 396

— , Election of, on auditing committee ci

— , Geologic names by 412

— ; Geology of the Taylorville region of Cal-
ifornia. 369

— , Letter from, on California peridotites 4:s2

— , I lea. ling of paper by 460, 511

— , Record of discussion by 460, 495, 51 1

report of, for committee on photo-
graphs 158

— , Referei to studies of " 103, 107

. Report of, for committee on photographs., itu

— . Titles of papers by 160

Dinotheru u i<iii the existence oi the) in

Roumania; G. Stefanescu 81

Distribi hok 1 1 nequalil 5 of) of i he eng lacial

drift; Warren Upham 134

I iE, .1. A., Analyses by 2

, Cited on 1 he Bainl Peter sandstone 1 i I

1 >• > k 1 cm Mr, . Cited on •• Black Earth "... 69

Dowlino, li B., Photographs by 182

Drift, englacial 134

phenomen; 1 in extra-morainic) ol

New Jersey: R D.Salisbury 173

Drought and winds (Effects of) on alluvial

deposits in New England; II. T. Fuller., lis

Page

Dumble, E. T., Acknowledgment to 217

— , Discussion of fossil plants from Texas by. 159

— , Donation of photographs by 472

— ; Notes on the geology of the valley of the
Middle Rio Grande. 21a

— , Title of paper by 183

Dumont, Amiuk, Cited on geology of Rou-
mania 81

Dutton, C. E., Cited on term isostasy 501

Dybowski, W., Cited on Paleozoic canals l'5i'.

Dyer, C. B., Quoted on Scolithus 38

Eagle Pass division, Description of the 224

, Geology about 220

, Section near 22.".. 227

Eakins, L G., Acknowledgments to 233

—, Analysis of eleolite-syenite by 211

Earseman, W., Cited on natural gas 204

the origin of petroleum 19:i

East Pitcairn, Pleistocene shore lines near.. 489
Echinanthtjs <ju i nqut frri.a redefined 105

ECHINODERMS, 1 Mst l'il llltlOIl Of 10]

Edwards, J. Milne, Cited on Paleozoic corals. 255

EHRENBERG, C. <'.. Cited On Paleozoic corals. 254

Eichwai.d, Kin w;i> von, Cited on fish re-
mains 59

Eldridge, G. H., Cited on Montana rocks... 202

the Harding sandstone 164

Election of Fellows 2

Officers and Fellows 454

Eleolite-syenite of Litchfield, Maine, and
Hawes' Hornblende-syenite from Red
Hill, New. Hampshire;" W. S. Bayley 231

— (The) of Beemerville, New Jersey : J. F.

Kemp 83

Elliot, H R., Quoted on geology of Alaska.... 4'.i7

Ells, R. W., Photographs by.... 18 .

Elm creek. Section on 226

Emerson. B. K., cited on eleolite-syenite 84

— , Discussion of isostasy by * 504

Stockbridge limestone by 583

— , Record of discussion by 495, 51 1

— , Resolution of thanks by ... 522

Emmons, S. F., cited on Paleozoic fossils 153

Engelmann, G., Cited on prairies 7:;

Emu, ami. Fossil coral from 264

— , Shell beds in 505

K\ imi.iim costatum, Naming of s] ies In;

— meeki, Naming of species 402

Eocene deposits of Cull' slope 128

the Plains 519

Texas n5

echinoid faunas 104

— iron ores i;,

— , Middleton formation of the 511

Eqi is beds of the Plains 519

Eriptychitjs americanus. Founding of species 167

Eruptive rocks of Alaska 496

California 376, 121

Montana 449

l-'.s. ondidu beds, Descripti f 227

Ivi keridge, Robert, Jr., Cited on the Jurassic

of Australasia 109

la i; via ra:i a beds (The i of < lesel compared
with those of North America; Friedrich

Sclmii.lt 59

Kv.'ii i ion, S\ llabus of |i i >n 7

Fairbanks, ll. W., Cited on California un-
conformities

!•' viia mi. n, II. L., Donation ol photographs
by

— , Election of, as Secretarj i i

— ; Proceedings of the fourth Annual Meet-
ing, laid at Columbus, Ohio, D< mber

30 and 31, 1891

Summer Meeting, held ai Wash-
ington, \ 1 1 ur 1 1 - 1 21 and 25, Isal 1

Fairview, Section tl 191

I'm i h\.. in i tlifornin roi ks

i ire en mountains >17

l.\ XII— Bum \ i

53 1

BULL. GEOL. SOC. AM.

Page
Fu n \. Jurassic and Cretaceous 61

— (Preliminary notes on the discovery of

a vertebrate) in Silurian (Ordovician)

strata: ('. D. Walcoti L53

Faunas .Tin* relations of the American and

European echinoid); J. \V. Gregory 101

Faxon, Walter, Cited on Jurassic fossils 402

ma; river district, Rocks of 421

Featherstonhaugh, c,. \V., Exploration by,

cited 333

Fellows, Election of. -. 155

— . List of 52i

Fish remains. .Silurian 153

l"i i mim;. Sandford, Cited on glacial lakes.... 4*4

Florida. Formations of 128

F.i! iiste, A. F., Cited on Cambrian fossils 517

Fontaine, W. M., Cited on California fossil

plants 389

fossil plants from Montana 323

Permian fossils 217

Triassic plants 24

— , Fossil determinations by :;74

— , Quotation from, on Permian Mora 218

Foreman beds, Description of 373

F\issil bones from Tennessee 121

— , Devonian 512

— horizons in California 4.'i9

— plants from Montana 223

the Wichita or Permian beds of

Texas; I.C.White 217

Fossils. Alaskan 498

— , Cambrian 516

— . Carboniferous 309

— , Echinoid lO'l

— , Jurassic 428

— , Jurassic and Cretaceous 61

— , List of Carboniferous :;:.".

Permian 218

Silurian 158

— , Lower Silurian 361)

— , Mesozoic. 15, 24. 62, 397

— , Miocene 93

— of Roumania 81

the Blue limestone 361

Butt' limestone 360

Potsdam sandstone 340

— . Paleozoic 32

— , Pleistocene 67, 505

— , Revision of Paleozoic 253

— . Silurian 69,376

— , Triassic 23

— , Vertebrate l'-'l

Fremont limestone, Definition of 154

Fl i i.iii bed, Description of 363

Fuller, H. T.; Effects of droughts and winds

on alluvial deposits in New England 148

Gabb, W. M., Cited on California fossils 397,

414. 4:;>'.. 138

Garber, John, Acknowledgment to 189

Gas, Pressure of natural 214

i.i er, Gerard de, Cited on Pleistocene sub-
mergence 51 1 1

terraces 487

— ; Quaternary changes of level in Scandi-
navia 65

Geikie, A., cited on overthrust faults 393

— , Quoted on quartz grains 351

Gemmelaro, G. G., Cited en Sicilian paleon-
tology 15

Genus, Description of 165

— , Naming of new 398

— . Revision of 2".:;

Itirvu i.i a gigantea, Naming of species 402

— linearis, Naming of species W2

— . New species of 405

Gibbs, George, Cited on zircons 234

Gilbert.G. K., Addresses by 2

— . cited on deformation....'. 66

drift 142

Page

Gilbert. G. K., Cited on glacial lakes 484, 4'.il

Iroquois shores 495

Pleistocene beaches 486,488

the Henry mountains 148

— . Discussion of Iroquois shores by 192

isostasy by 503

— . Election of, as President 454

— . Record of discussion by 31, 67, 459,

460, 465, 495, 504

remarks by 522

i.i li i m. action. Discussion of 179

— deposits 134. 505

of South America 14

— lakes, Channel- not evidence of 491

Warren. Algonquin, Iroquois and Hud-
son-* hamplain (Relationship of the):
Warren Upham 484

Glaitatiox in Montana 446

Glaciers of Alaska 496

Greenland, Condition of 138

Glyphjea punctata, Naming of species 402

Gneiss (Secondary banding in); W. H. Hobbs. 460

Goeppert, EL, Cited on Scolithux 34

Goldfuss, ^. A., Cited on Paleozoic corals.... 251

Gold of the Sierra Nevada 411

Goniomya, New s] ies of 402

Goodchild, J. G., cited on Pleistocene sub-
mergence 510

Gottsche, C. M., Cited on the Jura of South

America 109

Grammoceras, New species of 405

Gkandeau; Fens, cited on calcareous soils.. 80
Graa els (On the northward and eastern ex-
tension of the pre-Pleistocene) of the

Mississippi basin ; R.D.Salisbury 183

Great Barrington, Geology of 462

Great Falls coal field 301

— formation, Age of 322

Gre \t Plains (A contribution to the geology

of the); Robert Hay ....519

Gf.eene, G. K , Dedication of species to 271

Greenland, Glaciers of L39

Gregory, J. W ; The relations of the Amer-
ican and European echinoid faunas 101

Greylock (Mount), Geology of 461

Grizzly quartzite, Description of 376

Gryph i;\ bono liformis, Naming of species... 107

— curtici. Naming of species 408

Guffey, J M.. Acknowledgments to 195, 211

Gulf oe Mexico (The) as a measure of isos- •

tasv: W .1 McGee 5oi

Hager, A. D., Cited on Cambrian rocks

Haim'e, Jules. Cited on Paleozoic corals

Hai.demann. S. S., Quoted on Scoli/hus

Hall, 0. W.. and F. W.Sardeson: Paleozoic

formations of southeastern Minnesota...

— , Cited on the Trenton limestone

— , Discussion of Paleozoic formations by....

— , Title of paper by

Hall, James. Cited on Coal Measures

Iowa stratigraphy

Kaskaskia limestone

— Paleozoic corals

Scolitlfus

supposed Huronian rocks

Warsaw beds

— . Discussion of Silurian fish remains by...

— . Founding of Potsdam by, cited

— , Letter from, on Chonophyllum

— , Quoted on Palasasler eucharis

Hai.hbia bed. Description of

Halysites eatenulatus, Use of in correlation..

Hamilton shale, Definition of.

il irdgrave sandstone, Description of.... 37:!.

Harding sandstone, Definition of.

Harker, Alfred; Thermometamorphism in

Igneous rocks

Harlan, Richard, cited on Me.qalonyx

Harrington, M. W., Acknowledgments to....

.-.if.

2.". I

:;::i
367
464
464
120
288
2a7
257
:;:;
335
2:1:;
170
336
281
512
399
L63
289
mi

151

12:1

335

INDEX To VOL.

.-,:;:,

Page

Hartt, C. F.,Reference to collections by 14

II m:i z mine, Section near the 225

Hawks, G. W ., Cited on eleolite-syenite 231

— . Quoted on hornblende-syenite 24:i

Hay, Rom in : A contribution to the geology

of the Great Plains _ 519

— , Cited on Tertiary deposits 88

— , Donation of photographs by 47:;

— , Record of discussion by 81, 148

— ; Sandstone dikes in northwestern Ne-
braska 50

Hates, C. W., cited on overthrusl faults 383

— ; Notes on the geology of the Yukon basin. 195

— . Reading of paper By 1'60

— . Record of discussion by 460

Heilprin, Angei.o, ( lited on Eocene mullusca. 47

Hemientolium, Naming of genus 398

Hereon, C. L., Analysis by 348

Sicks, I.. E., < ited on sandstone dikes 50

Highbkidge, Ex t r. i-iu. .rain ie drift at 178

Hilgard, E. W., Cited <m Middleton forma-
tion all

— , Discussion of'black earth" by so

— , Record of discussion by 67, L34

— ; The Cienagas of soul hern California 124

— , Title of paper by 51 2

Hill, R. T.. Cited on sandstone dikes 55

Texas and Mexico 483

— ; Notes on the Texas-New Mexican region. 85

— , Record of discussion by 14

Hillebkand, W. P., Acknowledgments to 232

— , Analysis of hornblende-syenite bj 249

Him hm.sn tuff, Description of 27,;, 4u7

IIiki k. < '. EL, Cited on Cambrian rocks.. 515

drift 135

Scolithus 36

— . Record of discussion by 133

— , Work of, in connection with library 469

Hitchcock, BDWARD,Cited on Cambrian rocks 515

glacial deposits L40

— Scolithus 32

Hobbs, W. H , rircd on Cambrian rocks 519

— , Donation of photographs by 474

— : Secondary bandings in gneiss 4t;o

Hulm, Gerhard. Cited on Hhore lines 67

Holmes, J. A., Record of discussion by 133

Hoi. st, X. (")., i ited on glacial deposits 138

sandstone dikes.. 55

IIoUNHI. KNDK-SYKM I F. from XeW 1 1 a Hips 1 1 I IV.. 2:11

Hortvet, Julius, Analysis by 351

Hosselki a limestone, Description of 374, 399

Hi dson-Champlain lake 1-1

Hikii.i. E. M., Reference to oil well of 197

Hunt, T. S., Cited on formation of geodes... 18

ScolitMs 39

the origin of petroleum 193

IIitton, \V.. Cited on thermometamorphism 16

Hyatt, Alphi us, Cited on California geology. :'.7l

Jurassic fossils. :\~.',

the succession of Jurassic rocks 382

Jura of South America 109

Trias oi Taylorville .".7:1

— , Discussion of fossil plants from Texas

— ; Jura and Trias at Taylon ille, 1 ia., 395

— , Record oi discussion by 184

, Title of paper by 460

Ihmtoi irbons, Source of 188

II lei 11 in. - limestone, Structure of, 517

iction, Discussion of I7!i

Iddinos, -i P., Cited on dikes in the < razy

mountains '.. 151

Igneoi - rocks, thi r mei phism in Ifi

hi. iv. is, Pre-glacial gravels in 1-1

— , Prairies of 72

— , Scci ionn in

I \... 1 1: 1 mi - bed, I '• -'-nii! ion ol 1 he . ... 105

N iming ol „ 398

— C) limplix. Naming ol pi • ii 398

Page

Kii.ia.i vcial deposits 505

Iowa, Coal Measures of lis

— , Sections in 285

— , Paleozoic formation- of IC4

— , Stratigraphy of northeastern :;ii

Ikon or.-, Origin of. 47

(The Terl iary) of Arkansas and Texas ;

R. A. F. Penrose, Jr 44

I in Ma. 1 is lake 484

— shore 1 The 1 north of the Adirondacks ; J.

W. Spencer 488

[sobases, Definition of term 63

l-H-i ,-v. Measure of 501

Irving, R. D., Cited on nomenclature 4ii4

Pot-dam condition- .;.«;

-supposed Huronian rocks 335

— , Tribute to 455

Jackson, A. W., Quoted on Spanish peak

granite 421

Jackson, T. M., Line of levels by 197

Jabkel, Otto, icknowledgments to 1I>5

— , Discussion of .Silurian fish remains K',s

— , Record of discussion by 23

James, John, Acknowledgment to 338

James, J. P.; Studies in problematic organ-

i-m-— the eviiu- Scolithufi 32

James, IT. P., Quoted on Scolithus 10

Johnson gravels, Description of 372

Johnson, L. C, Record of discussion by 108

— ; The Chattahoochee embayment 12-

Jones, T. R., Cited on Scolithus ;i

Jordan sandstone, Definition of 342

Jui'D, J. W., Cited on thermometamorphism.. 16
Julien, A A., cited on geology of Massachu-
setts hi 1

Jura and Trias at Taylorville, California;

Alpheus Hyatt '. 395

Jurassic echinoid faunas 103

— of California 372

Montana 309

the sierra Nevada 425

— (On the Marine beds closing the) and

opening the Cretai 1-, with the history

01 their fauna ; A. Pavlow 61

.ii b i-Tri \-, « Correlation of the 23

— of South America 13

Texas 85

the F.a-t Indie- 1 1

K ins as, < reology of 5211

— , Prairie- of 80

Kaiu:, G. J., Resolution Of thanks to 522

— . Welcome to the Society by 154

Kakpinski, A., Cited on Russian paleontology 15

Kaska-km beds, Definition of. 295

Kin, i. i> S., Record of address by 16

— . Resolution of thanks to 522

Kkmp, J. I-'.. Announcement by 22

— : Memorial of John Prancis Williams... .. 155

— . < in committee on photographs l7o

— : The eleolite-syenite of Beemerville, New

Jersey 83

Kendall, P. !•'.. Cited on bowlders 506

Kentucky, Fossil coral from 271;

3 wells in 188

1 i% limestone, Definition of 292

- tion at 285

K 1 1 1 1 -, . Fossils from 505

K111-. C. R., Cited on Coal Measures 120

Osage linie-t jal

; I he Principal Mississippian section

— . Title of paper by 133

Kindkhiiook bed D finition of 287

Kino, Ci ucenck, Cited on California geology.. 370

post-Carboniferous epeirogeny :!7a

Klamath mountains, Firsl use of name cited .71

Ki \iaii:. II G , Analysis of sandstone by..

Iv i.kim 1 iHL, Tribute to 151

536

BULL. GEOL. SOC. AM.

Page
Knowltox, F. 11., Cited on Cretaceous fossil

plants 330

fossil plants 323

Konini'k. L. G. UK, Cited on Paleozoic corals.. 255

Kootame of Montana 309

Krapotkin, P.. < 'itcil mi glacial phenomena.. Tu
Kbassnof, A. N.; Tin- "black earth'' of the

steppes of southern Russia OS

Laccolites of the Crazy mountains 448

Lafayette formation, Continental oscilla-
tions represented by 502

in Texas .'. 230, 483

Lakes (Glacial), Evidence of 491

Lamplugh,G.W.,< Sited on glacial phenomena. 507

— , Collections by 61

Lane, A. C, Record of discussion by 22

Laramie rocks of -Montana 446

Las Moras creek, Section on 223

Lawson, A. C., Cited on drift 142

Lazenby, W. R., Resolution of thanks to 522

Lk Conte, Joseph, Record of discussion by... 55

Leidy, Joseph, Cited on Megalonyx 122

the geology of Texas 230

Lemberg, J , Cited on testing minerals 247

Lesley, J. P., Cited on gas pressure 190

Pocono sandstone 192

Scolithus 80, 41

— , Criticisms of "anticlinal theory" by 215

Lesquereux, Leo, Cited on prairies 7?.

Leverett, Frank, Cited on drift 135

— , Record of discussion by 134, 151

Levy, Michel, Cited on thermometamor-

phism 10

Lewis, H. ('., Cited on Pleistocene submer-
gence 510

shell deposits 500

— , Tribute to 455

Liassic fossil from California 436

Library, Institution of a 468

Lima acuta, Naming of species 39S

— dilleri, Naming of species 404

— , New species of. 402, 405

— taylorenais, Naming of species 405

Lindahl, Josua, Cited on glacial deposits 138

Lindenkohl, A., Cited on submerged chan-
nels 486

Lindstrom, Gustay, Cited on Paleozoic corals 257

Litchfield, Eleolite-syenite of 231

Litchfieldite, Application of name 243

Lithographic limestone, Definition of 288

Little York. Extra-morainic drift at 177

Llano Estacaihi, Structure of the 85

Logan. Sir W. E., Cited on Scolithus :;4, :>7

Long, S. H., Explorations by cited 333

Lonsdale, Willi <m,( lited on Paleozoic corals. 255

Loper, S. W., Collections by 168

Lord, M. W., Resolution of thanks to 522

Loriol, Perceval, de, Cited onechinoids lot

Lossen, L. A., Cited on thermometamorphism 10
Loughridge, R. H., Cited on Texas deposits.. 92

Louisiana limestone, Definition of 289

— , Section at 286

Lower Magnesian, Abandonment of term 404

Lowkr Silurian, Composition of the 349

— , General section of the 359

Lundbohn Hjalmar, Attendance of, at Co-
lumbus meeting 522

Lyell, Sir Charles, Cited on glacial lakes... 484

McConnell, K. G. Cited on overthrust faults.. 393

McCoy, Frederick, Cited on Paleozoic corals. 255
Macfarlane, Thomas, Record of discussion

by 22

McGee. W J. Acknowledgment to :;4l

— , Cited on glacial episodes 181

kames.. 145

Oneota formation 341

Saint Peter sandstone 350

Page

Mi Gee, \V J, cited on Texas deposits 92

the Columbia formation 94, 230

— , Discussion of isostasy by 504

Paleozoic formations by 464

— the geologic formations of the Rio

Grande by 483

— , Election of as Kditor 454

— . < Irganization of party by 511

— , Reading of papers by 484, 508, 511, 512

— . Record of discussion by 492

— ; The Gulf of Mexico as "a measure of isos-
tasy 501

Maclurea bed. Description of. :;i>5

Macon, W. EL, Acknowledgments to 233

Magnesian formation, Application of term... 464

— series, Definition of. 340

Maine, Drift of l:;'.i

— . Eleolite-syenite of 83, 231

Manitoba, Drift of 141

M\NM.svrox (The) oil field and the history

of its development; I. C. White 187

Map (A geological) of South America ; iiiistav

Steinmann 13

Maquoketa bed, Description of 305

Marcou, Jules, Cited on the Mesozoic of Cali-
fornia 390

Jurassic of North America 409

Marr, J. E., Cited on volcanic rocks 17

.Marshall group, Note on the establishment

Of 9

Martin, W. S , Cited on altitudes 500

Massai hi setts, Cambrian rocks of 519

— . Drift of 140

— , Eleolite-syenite of. 83

— , Schistose rocks of 460

Meeds. A. D., Cited on Potsdam sandstone... 335
Meek, F. B., < lited on California fossils... 397, 414

geology 370

Jurassic fossils 409

of California 425,438

Kinderhook beds 287

Megalonyx (The Pelvis of a) and other bones
from Big Bone cave, Tennessee; J. M.

Safford... 121

Mell, P. H., Donation of photographs by :;72

Melville, W. H., Acknowledgments to 232

— , Analysis of eleolite-syenite by 238

Memorial of J. F. Williams 455

Merrill, F. J. H., Cited on Pleistocene ter-
races 487

— , Record of discussion by 134

Merrill, G. P., Acknowledgments to 233

— , Donation of photographs by 471

— , Resolution of thanks to. - 151

Metamorphism of igneous rocks 16

.Mexico iGuxf of), Tertiary rocks of the 47

Mexico, Remarks on the geology of. 483

— . Structure of northern.. 94

Meyer, Victor, Tribute to 456

Mi< higan, Episodes in the history of the uni-
versity of. lo

surveyof 8

Middleton formation (Note on the) of Ten-
nessee, Mississippi and Alabama; J. M.

Safford 511

Miller, Hugh, Cited on till formation 137

Miller, S. A., Cited on Carboniferous echi-

noids 102

Lingula 352

Paleozoic corals 257

— , Quoted on Scolithus 38

Mills, J. E.: Stratigraphy and succession of
the rocks of the Sierra Nevada of Cali-
fornia 413

— . Title of paper by 460

Milne-Edwards, J., cited on Paleozoic corals -J54

MlNDELEFF, CosMOS, Photograph by 481

Minis, Coal '. 31*

Minnesota, Drift of 14o

— , Paleozoic formations of 331, 464

— , Prairies of 72

INDEX TO VOL.

537

Page

Minshall, F. W., Cited on natural gas 204

on the origin of petroleum 19:3

Miocene deposits of Gulf slope 128

— faunas 105

— rocks of California 372

Mississippian section (The principal); C. I!.

Keyes 283

Mississippi basin, Pre-Pleistocene gravels in

the 183

— , Middle ton formation of oil

— river, Sections on 284

Missouri, Coal Measures (The) and the con-
ditions of theirdepositioii : Arthur Wins-
low 109

— . Prairies of 80

— , Sections in 287

Modiola, New species of 402

— triqacetraeformis, Naming of species 398

Mojsisovics, A., Cited on subdivisions of the

Trias 399

Mokositchia, Transfer of species to 105

Monotis bed, Description oi 397

Montana coal fields (Two): W. H. Weed 301

— , Geology of Crazy mountains in 44.5

Montgomery, A. J., Acknowledgment to 198

Montgomery limestone 376

MoNTLIVAULTIA (?), XoW Speojcs of 401

Moore, Charles, Cited on the Jurassic of

Australasia 409

Moraine, Drift beyond the terminal 17:;

Mormon sandstone, Description of 37::, 103

Morrei.l, H. K., Acknowledgments to 232

Morris, John, Cited on Paleozoic corals 256

Morton, S I ;.. < lited on echinoids 105

Mortonia rogersi redefined 105

Mount Bethel, Extra-morainic drift at 177

Mount Morris, Section at 189

Mum, John, Quoted on the geology of Alaska 499

Munthe, II.. Cited on shore lines 07

Murchison, R. I., Cited on Russian "black

earth" 6S

Eurypterus beds 59

Scolithus 36

— , Quotation from "Silurian System" of..... 255

Myacites, Now species of 398

Mytilus, New sr ies of 402, 404

Nansen. Fridtjof, Cited on Arctic ice 138

Nabon, 11. B., Tribute to 455

Nathokst, G. \., Cited on Scolithus 40

the glacial theory 7-

Natiral Bridge, Pleistocene shore lines

mar 4s!i

Natural bridges of Florida 132

n i rraska, Geology of 519

. Sandsl • dikes in 50

\ :ne deformation 85

— deposits of ' California :;?-

the Plains 519

Newberry, J. 9., Ago of Great Falls forma-
tion determined by 322

— . Cited on Coal Measures 120

fossil plants 302

glacial drift 304

lakes 184

Pleistocene terraces 187

Scolithus 36

the origin of petroleum 193

Uniu from Montana 310

\i.u Brunswick, lee work near 1 7: »

New England, Drifl of 139

— , Effects of droughts and winds in 148

New Hampshire, Drifl of L39

. Hornblende-syenite from -j::i

\ i w -i i rb! '. . Eleolite-syenite of 83

— , Extra morainic drifl in it:;

I i i.i — i • • of 26

\ i.u Mexico, Geology of 85

— , Triassic of ■!.<

New Richmond sandstone, Definition of 342

Page

Newton, Henry, Tribute to 155

New York, Drift of 14(1

— , Pleistocene shore lines in 488

Nicholson, H. A., Cited on Paleozoic corals.. 257

Nicollet, J. N., Exploration by, cited 333

Nikitin Serge, Cited on glacial phenomena.. To

Nii.es, W. H., Cited on rock stresses 519

Nordenskiold, A. E , Cited on Arctic ice 138

North Carolina, Triassic of 25

Norwood, J. G., Analysis by 158

— , Cited on Kaskaskia limestone 297

■ Paleozoic stratigraphy 284

unconformities 114

Noyes, W. A., Analysis by 158

Nucula tenuis. Naming of species 398

Oesel, Eurypterus beds of. 59

Officers, List of 523

Ohio, A deep boring in 150

On. field, The Mannington 1st

Omphyma, Discussion of genus JTT

Oneota formation, Relations of 312

— limestone, Application of term 404

Opis bed, Description of 4o:;

" Orange sand," Age of the 183

Organisms (Studies in problematic) — the

genus Scolithus ; J.F.James 32

Orthisina bed, Description of 264

Orton, Edward, Acknowledgment to L93

— , Cited on natural gas 209, 2J.5

— , On committee on Winchell resolutions... 13

— . Eulogium of Alexander Winchell by 56

— . Letter of acknowledgment from 500

— , Record of discussion by 151

— , Resolution of sympathy for 483

Osage limestone, Definition of 290

Ostrjea, New species of. 401

Ovehthkust faults 393

Owen, D. D., Cited on Kinderhook beds 288

nomenclature 4r>4

the term Subcarboniferous 284

■ Trenton I i mo-tone 3li7

— , Quoted on Saint Peter sandstone 351

— , Work of, in Minnesota :;31

OwiN, J , Acknowledgment to 219

Oxford Furnace, Extra-morainic drift at 175

OXYTOMA, New -peoios Of 407

Ozark uplift, History of the 110

Pal^.aster euchai 'is, Hall; A. H.Cole 512

Paleozoic formations of southeastern Minne-
sota; C. W. Hall and F. W. Sardeson 331

— corals 253

Pallas, P. S., Cited on "black earth" 68

Pander, c. 11.. cited on fish remains 59

Pattenburg, Extra-morainic drift at 178

Paul, E. G., Collections by 373, 396

Pavlow, A.; < in t In- Marine beds closing the

Jurassic and opening the Cretaceous,

u it 1 1 i he history of their fauna 61

Peale, A. C, Cited on the Oolite HO

Peart, R. K.. Cited on Arctic ice L38

I'm tin inexpectans, Naming of species 398

— lasseni, Naming of species 398

— , New species of 402, 405

I'eet, c. k., cited on striated bowlders 179

Pennsylvania, Extra-morainic drifl in 173

— .nil of 188

— , Triassic ol 25

Penrose, R. \. !•'., Jr., Cited on Texas de-
posits 92, 219

Reynosa beds - !i

— ; The Tertiary [ron Ores of Arkansas and

Texas o

l'i in mo in s altus, redefined 105

Pi n mian of Texas, Discussion of the I ■ B

— , Plants from the 117

— , Triassic and Jurassic Formations (On
the) in the Easl Indian Archipelago

\ II'-- n -i Rothpletz ii

o3S

BILL. GEOL. SOC. AM.

Page

Petroleum Age (The), Reprint from 208

Petroleum fieldj The Mannington 187

— , I >rigin of 202

Pettek, W. H.. Amendment to By-Laws pro-
posed by 470

— , Cited on geology of California 4:;.">

— , Record of discussion by 160

Phinmet, A. J., Acknowledgment to. 193

Pholadomya, New species of 402,405

Photographs, Report of Committee on 47n

Pictet. F. •!.. Cited on Paleozoic corals 256

Pike, L. M., Explorations by, cited 333

Pinna cuneiformis, Naming of species 4n4

— expansa, Naming of species 402

Pinto limestone. Description of. 222

Pitcaikn, Pleistocene shore lines near 489

Plains, f.eology of the 519

Pleistocene, boring in the 150

— changes of level 65

— deposits 124, 134

in England 505

, Interior 95

of California 372

New Jersey 170

Russia 68

the Plains 519

Texas 85

— (Pre-) gravels of the Mississippi basin 183

— subsidence 508

— terraces 4S7

Pi.k.uromya, New species of 402

Pliocene echinoid faunas 107

Pocono sandstone. Oil from the 188

Potomac flora, Derivation of the 25

Potsdam sand- tone of Minnesota 335

Powei.i, J. W.. Donation of photographs by.. 480

— , Cited on the Klamath mountains M74

Triassic do),, ,<its 25

Pribii.of islands (Geology of the); Joseph

Stanley-Brown ." 496

PflorEFDiNGS of the Fourth Annual Meeting
held at Columbus, Ohio, December 29.

:;n an. I 31, 1891 : H. L. Fairchild 153

Summer Meeting held at Washing-
ton. August 24 and 25, issl ; H. L. Fair-
child 1

Processes (Peculiar geologic) on the Channel

islands of California ; L. <•. Yates 133

PrF.RorENNA, New species of 404

Ptvchophvllvm, Discussion of genus 278

Publication, Rules relating to 4G7

Pumpellt, Raphaei, Reference to, as chief
of division 461

Quartz veins of California 44u

Quaternary changes of level in Scandi-
navia; G. de Geer 65

Quenstebt, F. A. von, Cited on Ammonites.... 4u4

Ravenkl, Edmund, Cited on echinoids... lo~>. 107
Rectus, Ei.isj'k, Cited on Russian steppes.... 8u

Kr.n Hill, Hornblende-syenite from 231

Red Lodge mines 320

— , Section at 3^7

Washington meeting 152

Reid, H. F., Cite,] on Alaskan glaciers 507

— , Donation of photographs by 478

Report of the Council 466

Reusi ii. Hans, Cited on rock structure 515

Revision of.the genus Chonophyllum 253

Rrynosa beds. Description of. 229

Rhabdoceras bed. Description of 398

— russelli, Naming of species 398

Rhacophvli.ites, New species of 4117

Rhynconella, New species of. 4114

— solitaria, Naming of species 398

R10 Grande (Notes on the geology of the

valley of che middle) : E.T. Dumble 219

Page

Robertson, l. B., Collections by I in

Robinson bed-. Description of. ::74

Rock species from Maine and New Hamp-
shire 231

Rocky Fork coal fields 321, 329

Roi kv mountain.-, Structure of southern 86

Roemer, F., cited on Texas deposits :i2

Rogers, H. D., cited on rode structure 208

Seohthus 35

Rogers, W. B., Cited on Scolithus 32

— Triassic plants 24

RohON, I., Cited on rish remains 59,169

Romingkr, Karl, Quoted on Paleozoic

corals 255

— . Specific name suggested by 274

RosENKtsc 11. II., cited on biotite 2:10

eleolite-syenite 81. 236

theralite. 450

— . Tribute to 456

R01 11, Justus, < lited on rock composition 19

Rothplf/iz, August; On the Permian, Tri-
assic and Jurassic formations in the

Hast Indian Archipelago 14

Ion ri. Formations of 14

Roumania, I>inotherium in 81

Ruprkcht, F. J.. Cited on "black earth" 69

Russell, 1. C, Acknowledgments to 396

— , Cited on Alaskan glaciers 507

— California geology 371

glacial deposits 138

— , Collections by 15:;. 395

— . Dedication of species to 398

— . Discussion of Iroquois shore lines by 4:i4

— , Photographs by '. 480

— , Record of discussion by 193

— , Title of paper by 165

Russia, " Black earth" of southern 68

Rutland, Geology of 515

Saffobd, J. M : Note on the Middleton for-
mation of Tennessee, Mississippi and

Alabama 511

— ; The pelvis of a Mcgalonyx and other

bone- from Big Bone cave, Tennessee... 121

— . Title of paper by 121

Saint Ei.ias mountains. Structure of 495

Sainte Genevieve, Section at 2s7

Saint George island, Geology of 498, 499

Saint Lawrence limestone, Definition of 342

— valley, Glacial lakes of 486

Saini I. "tis limestone, Definition of 294

— , Section at 286

Sainte Mary, Section at 2S7

Saint Paul island, Geology of 496

— , Section at 354

Saint Peter sand-tone. Definition of. 350

Salisbury, R. D. : Certain extra-Morainic

drift phenomena of New Jersey 173

— . Cited on drift 136

the driftless area 332

— ; On the northward and eastern extension

of the pre-Pleistocene gravels of the

Mississippi basin 183

— , Title of paper by 134

— , Record of discussion by 133

Salomon, Alexander, Cited on thermometa-

morphism 16

Salter, J. W., Cited on Scolithus :;.">

S \ s in m i.hf. Section at 314

Sandstone dikes in western Nebraska; Rob-
ert Hay 50

— . Purity of the Saint Peter ''"'1

San Miguel beds, Description of 224

Sarukson, F. W.. < lited on the Rower Silurian 358
—, Finding of Saint Peter fossils by 352

— (C. W. Hall audi: Paleozoic formations of

southeastern Minnesota 331

— . Title of paper by 164

Saukr, A., cite. i on thermomet imophism.... 16
Scandinavia, Changes of level in 65

IXDEX TO VOL. 3.

539

Page

Schluteb, Carl, Acknowledgments to 257

Schmidt, V., Cited on shore lines.. (iT

Schmidt, Fkiedrich, Discussion of Silurian

fish remains by 168

— , Record of discussion by 23

— ; The Eurypterus beds of Oesel as com-
pared with those of North America 5!)

Schwatka Frederick, Exploration by 495

Science, Reprint from 206

Scolithu6 ctintonensis, Proposal of name 33

— minnesotensis, Proposal of name 41

— minutus, Description of 38

— , Review of the genus 32, 43

— sheperdi, Proposal of name 32

Scutklla rogersi renamed 105

Seal islands, Cxeology of the 490

— , Transportation of pebbles by the 497

Sekly, H. M., Quoted on Scolithus 4^

Selwvn, A. R. C, Donation of photographs

by 481

— , Cited on Canadian oil fields 194

Serpentines of California 430

Shakopee dolomite. Definition of 342

Shaler, N. S , Cited on drift 143

— , Record of discussion by 44, 133

Sheldon, E. P., Analysis by 348

Shell lied (Supposed inter-glacial) in Shrop-
shire, England ; G. F. Wright 505

Sherrlll, J. G., Cited on drift 144

Sherzer, YV. H.; A revision ami monograph

of the genus Chonophyllum 253

— , Record of discussion by 504

— , Title of paper by 484

Shoo-fly beds, description of 375

Shropshire, Shell beds in 505

Shumard, B. F., Analyses reported by 348

— , Cited mi Cambrian conglomerates 336

Osage limestones 290

Saint Louis limestone 294

Texas deposits 92

unconformities 107

Sin hard, If. < r., cited on Pi coid io peak li'.i

the Jornado basin , 97

sum HER, I . K„ Analysis by "34*

Sierra Nevada, Rocks of the 413

— , Structure of the 370

Sihleano, Stefan, Translation by 81

Sni kian formations of Minnesota 464

— fish remains 59

— of California 372

Minnesota 332

the i rreen mountains 5 11

— vertebrates 153

Simonsohn, , Collections by 59

Sismomjia marginalia renamed 105

— plana renamed 105

SjOoren, A., Cited on European oil fields 194

Smith, B. k.. Cited on Middleton formation., .mi

Smith, m. M., Acknowledgments to -■:;:

— , Collection by 244

s mii a, W. C., Analysis by 348

Smock, -I. C, Cited on extra-morainic drift... iti

— , El eet ion of, on auditing committee 454

South Ameru \, Geologic map of , 13

South Colton, Pleis me shore lines near.. 189

8owter, T. w. E.j Cited on Scolithus 11

Spi 1 11 -. Description of 38

. Founding of 165,275

— , Naming ol 41, 397

- Renaming of :;•_•, 3 ; 1, ,

Spencer, J. W.; Channels over divides nol

evidence perse of glacial lakes 101

— , Cited on bowlder pavements 66

glacial takes 184

Pleis! ne shore lines 103

— , Discussion of Iroquois Bhore lines by 194

— ; Tie- Iroquois shore north of the Adiron-
dack n 188

Spehr, !•'. \V., Resolution of thanks to 522

Bph 1 1; :\- i" 'I. Description of 103

New species of 105

Page

Stanley-Brown, Joseph ; 1 S-eology of the Prib-

ilof islands 490

— , Photographs by tsl

Stanton, T. YV., Cited on fossils from Mon-
tana 310

— , Collections by 153

Stefanescu, Grbqoire ; On the existence of

the Dinotherium in Roumania 81

Stein, Robert, Translation by. 68

Steinmann, Gubtav; A geological map of

South America 13

— , Cited on the Jura of South America 409

Steppes, "Black earth" of the 68

Stevenson, J. J., Cited on Coal Measures 120

rock structure 208, 211

-the origin of petroleum L93

— , Honorary election of 169

Stictoporella bed, Description of. 361

Stic'toi'iika bed, Description of 362

St. John, Orestes, Cited on mount Capulin... 9!'
Stockbridge limestone (On the structure and

age of the) in the Vermont valley; T.

IN. Dale 514

Stoddard, S. R., Donation of photographs

by 474

Stokes, H. N., Analysis by 317, 321

Stone, <;. II., cited on kames 145

till 139

Stores, James, < 'ollections by 396

Straight coulee, Section in. 313

Stratigraphy and succession of the rocks of

the Sierra Nevada Of California; .I.E.

Mills 413

— of California 412,438

Montana 302

Minnesota 368

the Mississippi valley 298

Strong, Moses, Cited on the Potsdam sand-
stone 340

Si i;i 1 tube of California rocks 387

gneiss -it;::

the Sierra Nevada 415

Stockbridge limestone 514

Stub, Dionys, cited on Triassic plants 29

Stvlina alb", Naming of species 408

— bed. Description of 407

— intermedin, Naming of species 408

— minutn, Naming of species 408

— subjecta, Naming of species 408

— tertia, Naming of species 408

Surface, IT. a.. Resolution of thanks to 522

Swallow, G. C, Cited on Kinderhook beds... 288

unconformities 110, ill

Swearinger slate, 1 leseri pt ion of 374, 397

Sweden', Fossil coral from '_'57

Sweet, E. T., Cited on the Potsdam sand-
stone

Synclinal folds in northern California 389

aff, J. A , cited on Reynosa beds 230

IBB, R, S., cited on mount Capulin 99

IYL0R1 hi i:. Jura and Trias at 395

■ region. Geology of the 369

slates. Description of 376

ennessee, Fossil bones from 121

. .Middleton formation of 611

Kit RACKS, Pleistocene |s7

BBTiABi beds of Nebraska 51

Roumania Bl

South America 13

gravels of the Mississippi basin 183

iron ores ii

I XABQ1 'reek, Seel ion on 223

i \ \s. Creti s formations of 621

. Fossil plant- from 'JIT

■.Geology of 219

-, Iron ores of ii

- -New Mexican region (Notes on the : R.

t. inn :

-. lien the geologj of 183

540

BULL. GEOL. SOC. AM.

Page

Theralite in tlie Crazy mountains 450

Thermometamorphism in igneous rocks ; Al-
fred Harker 16

Thompson limestone. Description of. - :;7:;. k)3

Tierra mi. am a. Definition oi term 8!)

Tiffany, A. s.. Record of discussion by Si

Timor, Formations of * 14

Tornebohm, A. E., Cited on rock structure... 238

Trail beds, Description of . ::74

Trask, J. D., Collections by 414

Trenton fish remains 158

— limestone, Analyses of 358

, Definition of 356

T i ; i is and Jura of California 395

— (The plant-bearing deposits of the Amer-

ican); Lester F. Ward 23

— of Alaska 495

California 372

Trigonia bed, Description of 406

— naviformi8r Naming of species 407

— . New species of 402, 405

— oblit/ua, Naming of species 4n7

— plumasensis. Naming of species 4<>7

Tschernyschew, Th., Cited on European oil

fields 194

Tuomey, M., Cited on echinoids 105, 107

Turner, H. W., Cited on California geol-
ogy 371, 372

faulting 393

Tyrrell, J. B., Photographs by 482

Ulrich, E. O., Cited on Trenton shales 349

Unconformities in California 378

Minnesota 353

the Sierra Nevada 428

Upham, Warren, Acknowledgments to 335

— . < lited on < lambrian conglomerates 337

glacial lakes 491

Minnesota stratigraphy :;4l

mountain structure 452

Pleistocene terraces 487

— ; Inequality of distribution of the engla-

glacial drift 134

— , Record of discussion by 133

— , Reference to field work of 493

opinions of 488,490

— ; Relationship of the glacial lakes Warren,
Algonquin, Iroquois and Hudson-Cham-
plain 484

— ; The Champlain submergence 508

Upson clays, Description of 224

Val Verde flags, Description of - 221

Vandergrift, J. J., Acknowledgment to 193

Van Hise, C. R., Cited on interstitial

growth 336, 345

-"—supposed Huronian rocks 335

— . Committee on Winchell resolutions 13

— , Eulogium of Alexander Winchell by 58

— , Record of discussion by... 22, 55, 124, 127, 134

— , Resolution of thanks by 151

Vani'xem, Lardner, Cited on Scolithus 33

Vermiceras crossmani, Naming of species ... 411

Vermicular sandstone. Definition of 288

Vermont, Stookbridge limestone of 514

Verrlll, A. E., Cited on Paleozoic corals 262

Vertebrates, Silurian 153

Virginia, Triassic of 25

Volcanic areas of New Mexico 98

— rocks of California 370. 421

Lake district 22

Yi lcanism in Alaska 495. 496

Montana 448

\V \ m;kn, W., Cited on Indian paleontology... 14

the Jurassic of India 409

Wachsmtjth, Charles, Letter from, on Cali-
fornia fossils 428

Page
Wadsworth, M. E., Cited on peridotites from

California 431

Walcott, C. D., Cited on aire of "Quartz

rock" 37

■ California fossils :;7i

Carboniferous fossils. 308

Scolithus 34,42

— . Identification of fossils by 375. 376, 516

— , Photographs by 480

— ; Preliminary notes on the discovery of a
vertebrate fauna in Silurian (Ordovician)

strata 153

— , Record of discussion by 55

— , Title of paper by '. 23

Wanner, Atreus, Cited on Scolithus 41

Ward, Lester F., Discussion by 15

— , Record of discussion by 31

— ; The plant-bearing deposits of the Amer-
ican Trias 23

Warren, Lake 484

Warsaw beds, Definition of 29:;

— , Section at 286

Watertciwn. Pleistocene shore lines near.... 488

Webb bluff, Section at 228

Weed, W. H., Cited on Cretaceous rocks of

Montana 446

Montana coal fields 309

■—, Photographs by 481

— ; Two Montana coal fields 301

Welling, J. C . Welcome on behalf of 2

Weston, T. C, Photographs by 48i

West Virginia. Oil field in... '. 187

— , Permian fossils of. 217

Wheeler, G. M., Cited on altitudes 41s

White, C. A., Cited on Carboniferous fossils.. ".08

Coal Measures 120

Cretaceous fri-sli water fossils 330

of Texas 224

geology of California 414. 425. 4::.S

■ — Jurassic fossils 409

Kinderhook beds 289

■ Osage limestone 291

Permian fossils 217,459

— = principles of correlation 44

Saint Louis limestone 295

supposed Huronian rocks 335

unconformities 110

— , Committee on Winchell resolutons 13

— , Discussion by 14

— , Eulogium of Alexander Winchell by 58

— , Quoted on Paleozoic corals 272

White, I. C, Cited on Coal Measures 120

the "anticlinal theory" 193

— , Discussion of isostasy by 503

— , Election of, as Treasurer 454

— ; Fossil plants from the Wichita or Per-
mian beds of Texas 217

— , Record of discussion by 460

— ; The "anticlinal theory" of natural gas.. 204
— : The criticisms of the "anticlinal theory"

of natural gas 215

— ; The Mannington oil field and the history

of its development 187

— , Titles of papers by 459

Wiin 'eaves, J. F., Acknowledgment to 269

White River formation in Nebraska 519

Whitfield, R. P., Cited on Carboniferous

fossils 309

Jurassic fossils 410

— Paleozoic corals 257

Scolithus 39

Whitney, J. D., Cited on altitude of mount

Whitney 410

Ammonites colfaxii 436

California geology 370, 397, 414, 438

prairies 73

quartz veins 442. 414

the Sierra Nevada 419. 42".

— , Quoted on the Sierra Nevada 420

Win in, esf.y, C. C, Cited on glacial lakes 484

Wn an \ beds, Discussion of 459

INDEX TO VOL. 3.

541

Page

Wichita beds. Plants from l'17

Wm.i jams, G. H., Donation of photographs by. 571

— . cited on thermometamorphism 10

— , Record of discussion by 84

Williams, H. 8., Cited on Kinderhook l>eds.. 289

name M ississippian 28.3

Osage limestone 290

— , Collection by 323

— , Election of, as councillor 454

Williams, J. P., Cited on eleolite-syenite 84

— , Record of death of 466

discussion by 84

— (Memorial of); J. P. Kemp 45.",

Willis, Bailey, Resolution of thanks to 151

— , Title of paper by 55

Winchell, Alexander, Acknowledgment to.. 254

— , Cited on name M ississippian 283

— , Eulogium of 56

— . Memorial sketch of 3

— , Portrait of facing 1

— , Record of death of 466

Winchell, 11. Y., Analyses by 358

Winchell, N. H., Acknowledgments to 335

— , Cited on Cryptozoon 344

drift 14J

glacial deposits L38

Minnesota stratigraphy 341

prairies 73

Seolithus 41

the Potsdam sandstone 339

— , Election of, as councillor 454

— , Finding of Saint Peter fossils by 352

— , Memorial sketch by 3

— , Record of discussion by 134

Winds and drought, Effects of 148

Wing, Augustus, cited on Seotilhus 38

the Stockbridge limestone 518

Winslow, Arthub, Acknowledgments to 287

— , Record of discussion by.. .. 459,495

— , Resolution of sympathy for Professor Or-
ton by 4x3

Page
Winslow. Arthur; The Missouri Coal Meas-
ures and the conditions of their deposi-
tion 109

Wisconsin, Paleozoic formations of 404

Wolff, J. E., Cited on Cambrian rocks 515.

517,518

geology of Massachusetts 401

Rocky Fork coal fields ... 325

the Crazy mountains 440

— , Discussion of secondary banding in

gneiss by I'd

— , Exhibition of views by 465

— , Reading of paper by 514

— , Record of discussion by 55, 84. ):•■_'. :,1]

— ; The geology of the Crazy mountains,

-Montana 445

— , Title of paper by 495

Woodhull, D. S., Dedication of species to 411

Wohthen, A H.. Cited on Kaskaskia lime-
stone 297

Kinderhook beds 287

Tertiary gravels 186

Worthington, John, Acknowledgment to 191

Wright, A. A., Identification of fossils by 505

Wright, It. f.. Record of discussion by 465,

49l', 504
— ; Supposed inter-glacial shell beds in

Shropshire, England 505

— , Title of paper by 504

Wykoff bed, Description of 366

Yates, L. <t. ; Peculiar geologic processes on
the Channel islands of California 133

Yukon basin (Notes on gcolosv of the) ; C. W.
Hayes 495

Zittel, Karl vox, Cited on Paleozoic corals . 257

— , Discussion of Silurian fish remains by ... 168

— , Record of discussion by 23

Zygospira bed. Description of 363

I.WI1I Bum Si

\m Vol 1801

New York Botanical Garden Librar

3 5185 00257 9223

Internet Archive Audio

Featured

Top

Images

Featured

Top

Software

Featured

Top

Texts

Featured

Top

Video

Featured

Top

Mobile Apps

Browser Extensions

Archive-It Subscription

Save Page Now

Full text of "Bulletin of the Geological Society of America"

See other formats